WO2007080980A1

WO2007080980A1 - Ball bearing for spindle pivot section of machine tool, and spindle pivot device of machine tool, using the same

Info

Publication number: WO2007080980A1
Application number: PCT/JP2007/050343
Authority: WO
Inventors: Yoshiaki Katsuno; Mitsuho Aoki
Original assignee: Nsk Ltd.
Priority date: 2006-01-13
Filing date: 2007-01-12
Publication date: 2007-07-19
Also published as: US20090131235A1; CN101341347A; KR101057311B1; EP1972801A4; EP1972801B1; EP1972801A1; KR20080084893A; CN101341347B

Abstract

Provided are a ball bearing for a spindle pivot section, adapted to be compatible with machine tools with recent tendency of having composite functions while keeping or improving functions of high accuracy (high rotational accuracy), high rigidity, low torque, and low heat generation, and a spindle pivot device of a machine tool, using the ball bearing. In the ball bearing, when it is a single-row ball bearing, the cross-sectional area ratio (B/H) between the cross-sectional width B in the axial direction and the cross-sectional height H in the radial direction is set to (B/H) < 0.63, and when it is a double-row ball bearing, the cross-sectional ratio (B2/H2) of the cross-sectional width B2 in the axial direction and the cross-sectional height H2 in the radial direction is set to(B2/H2) < 1.2.

Description

Specification

Ball bearings for machine tool spindle turning parts and machine tool spindle turning devices using the same

Technical field

[0001] The present invention uses a ball bearing for a spindle turning device of a machine tool that performs turning, grinding, lapping and the like in a machine tool represented by a milling machine, a lathe, a grinding machine, and a lapping machine, and the same. The present invention relates to a spindle turning device for machine tools.

Background art

[0002] In the case of a spindle turning device that drives the spindle to turn on a machine tool such as a milling machine, a lathe, or a grinding machine, a work piece ( In order to improve the machining accuracy of workpieces (for example, roundness, cylindricity, inner and outer diameter dimensional accuracy), machined surface quality (for example, glossiness of the machined surface, texture, etc.), and machined surface roughness, The following functions are usually required.

(1) High accuracy (high rotation accuracy)

(2) High rigidity

(3) Low torque and low heat generation

In particular, machine tools with so-called numerical control functions (so-called NC machine tools) have become the most recent, and NC lathes, NC milling machines, machining centers that can handle various machining conditions with a single machine tool. In addition to NC machine tools such as these, complex NC machine tools with the function of a machining center added to NC lathes have also appeared. Multi-function machine tools such as machining centers and complex NC machine tools have more machine components and force than single-function machine tools in the floor space and height direction required by one machine. Space is big. Therefore, in addition to satisfying the functions (1) to (3) described above, components such as bearings are further required to save space.

[0003] In such a multi-function machine tool, it is considered to achieve multi-function by turning the spindle on which the tool is mounted, and a bearing used in the spindle turning device of such a machine tool. Conventionally, the following types are used. (1) Cross roller bearing (See Fig. 31)

As shown in FIG. 31, the cross roller bearing has a configuration in which a large number of cylindrical cores 3 are arranged between an inner ring 1 and an outer ring 2 so as to roll freely. It can receive axial load and moment load in both directions and save space.

[0004] However, in the cross roller bearing, the rolling element is a roller, and the rolling contact surface of the roller 3 is in line contact with the raceway groove la, 2a. Due to slight deformation when incorporated in uzing, the contact state of the line contact portion becomes unstable and torque unevenness occurs. In addition, for a spindle turning part of a machine tool, a preload is often applied to the bearing in order to achieve high accuracy and high rigidity, but in this case, the torque unevenness due to the above deformation becomes even larger.

(2) 4-point contact ball bearing (See Fig. 32)

As shown in Fig. 32, the four-point contact ball bearing has a configuration in which a large number of balls 6 are arranged between the inner ring 4 and the outer ring 5 so as to be able to roll. It can receive axial load and moment load in both directions, and can save space.

[0005] In the case of a four-point contact ball bearing, the rolling element is a ball, so when receiving a pure axial load, or when an axial load predominates over a radial load, the torque is smaller than the cross roller bearing of the same size, but the axial load When the radial load prevails against each other, or when receiving a pure radial load, each ball 6 comes into contact with the raceway grooves 4a and 5a at four points, so that the spin slip between the ball 6 and each raceway groove 4a and 5a occurs. The large torque is large. In addition, as with cross roller bearings, for the main spindle turning part of machine tools, preload is often applied to the bearings in order to achieve high accuracy and high rigidity. The torque further increases due to contact with the grooves 4a and 5a at four points.

(3) Two-row combination ball bearing (see Fig. 33)

As shown in FIG. 33, the two-row combination ball bearing has a configuration in which an anguilla ball bearing or the like in which a plurality of balls 9 are rotatably arranged between an inner ring 7 and an outer ring 8 is combined in two rows. In the case of two-row combined ball bearings, each single-row bearing has two points of contact between the raceway grooves of the ball 9 and the inner and outer rings 7, 8, so that torque can be reduced, but twice that of the single-row bearing. A space in the axial direction is required, and cross roller bearings are inferior to 4-point contact ball bearings in terms of compactness. [0006] Further, there is a two-row combination ball bearing having a configuration in which an extremely thin deep groove ball bearing is combined with an anguilla ball bearing (see FIG. 34) for the purpose of space saving. When using a two-row combination bearing with a combination of ultra-thin ball bearings to support the rotating shaft on the housing, the shaft is usually formed at the end of the shaft 11 as shown in FIG. The inner ring 7 of the two-row combination bearing is fitted to the stepped portion 12 and the free end of the inner ring 7 is pressed to the end of the shaft 11 by the inner ring presser 14 fastened with the bolt 13 to the rotary shaft 11. The inner ring 7 of the two-row combination bearing is fixed, and the outer ring 8 of the two-row combination bearing is fitted to the step 16 formed at the end of the housing 15 covering the rotating shaft 11, and the free end of the outer ring is fitted to the housing. The outer ring 8 of the two-row combination bearing is fixed to the housing 15 by being pressed by the outer ring presser 18 fastened to the end of 15 by the bolt 17.

[0007] For this reason, in the case of applying an extremely thin deep groove ball bearing shown in Fig. 34 as a two-row combination bearing inserted between the rotary shaft 11 and the nosing 15 to save space, Advantageous force Inner ring 7 and outer ring 8 are very thin. The inner ring 7 and outer ring 8 have low rigidity, so the machining accuracy is very low, especially roundness. 7 and the outer ring 8 are fitted to the rotating shaft 11 and the housing 15, and are pressed by the inner ring retainer 14 and the outer ring retainer 18 to be fixed to the rotating shaft 11 and the nosing 15. There is a problem that it takes time to secure the built-in accuracy that is easily deformed when fitted to the rotary shaft 11 and the housing 15 or when pressed by the inner ring retainer 14 and the outer ring retainer 18. Also, depending on the case, the inner and outer ring 7 and the outer ring 8 raceway grooves may be distorted due to deformation at the time of assembly, and an offset load may be applied between the contact portions between the balls 9 and the raceway grooves, and the smooth rolling movement of the balls 9 may be hindered. In some cases, it may cause a problem of being damaged by short-term driving. (4) Two-row combination tapered roller bearing (See Fig. 36)

As shown in FIG. 36, the two-row combined tapered roller bearing is a tapered roller bearing in which a plurality of tapered rollers 24 are arranged between a inner ring 21 and an outer ring 22 via a cage 23 so as to be capable of rolling. The inner ring spacer 25 and the outer ring spacer 26 are combined in two rows. The roller bearing is a roller S rolling element as in the case of the cross roller bearing. The rolling contact surface of the roller 24 is in line contact with the raceway groove, and the end of the roller 24 and the inner ring 21 are in contact with each other. Since the flange 27 is in sliding contact, the torque increases, and twice the axial space of the single row bearing is required. is there. In addition, in order to achieve high accuracy and high rigidity in a main spindle turning part of a machine tool, a preload is often applied to the bearing, but in this case, the torque is further increased.

[0008] As a conventional spindle turning device of a machine tool, for example, as described in Japanese translations of PCT publication No. 2004-520944 (hereinafter referred to as Patent Document 1), a mechanical structure centered on a vertical first axis is used. The first half head pivots relative to the first half head via a guide bearing on an inclined plane inclined at 35 ° to the horizontal plane to support the tool spindle and is perpendicular to the inclined plane A second half head that swivels around the second axis with respect to the first half head, and a direct motor that swivels the first and second half heads separately. There is also known a spindle head that can rotate between two axes in a state where the second half head is swiveled to rotate the tool spindle so that its central axis is at an elevation angle with respect to the horizontal plane.

[0009] Further, as an example of the rotary table, as described in Japanese Patent Application Laid-Open No. 10-29125 (hereinafter referred to as Patent Document 2), the table is mounted on a support shaft standing at the center of the base. Rotation indexing, which is inserted through a distributor, is rotatably supported by a cross roller bearing on the base, and the table is rotationally driven by a worm gear or direct motor. The device is known.

Disclosure of the invention

[0010] Thus, by adopting the configuration described in Patent Document 1 and Patent Document 2 described above, various processing can be performed on the upper surface in addition to the four side surfaces (work material (workpiece)) Machining center can be used to manufacture multi-tasking machines with both NC lathe and machining center functions. Although the number of machines is increasing, the performance of the support bearing that supports the rotation has the most influence on the characteristics such as the rotational accuracy and rigidity of the rotating mechanism regardless of which configuration is adopted.

[0011] Further, in order to achieve the above-described configuration, the space for the components around the swivel mechanism must be increased, and thus further space saving is required. Furthermore, in order to reduce the power for swinging the entire main shaft as much as possible and to save energy, it is necessary to reduce the weight and reduce the inertia by the compactness of the turning mechanism. However, as described above, when a cross roller bearing, a four-point contact ball bearing, a two-row combination ball bearing, a two-row tapered roller bearing, or the like is applied as a support bearing, various problems occur. As a result, there is an unresolved problem that it is not possible to construct a ball bearing for a spindle turning part corresponding to a recent compounding machine tool while maintaining or improving the functions (1) to (3). There are challenges.

[0012] Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and the recent trend toward compounding while maintaining or improving the functions (1) to (3) above. It is an object of the present invention to provide a spindle bearing ball bearing for a machine tool and a spindle machine for a machine tool using the same.

In order to achieve the above object, a spindle bearing ball bearing for a machine tool according to claim 1 is used for a spindle turning section of a machine tool, and a large number of balls are provided between an outer ring raceway groove and an inner ring raceway groove. Is a single-row ball bearing that is arranged so as to be able to roll, and the cross-sectional dimension ratio (BZH) between the axial cross-sectional width B and the radial cross-sectional height H is (BZH) <0.63 It is characterized by

[0013] In addition, the ball bearing for a spindle turning part of a machine tool according to claim 2 is characterized in that, in the invention according to claim 1, a seal housing groove is formed on at least one side end surface between the outer ring and the inner ring. An annular seal body is disposed in the seal housing groove, and a cage for positioning the plurality of balls in the circumferential direction is disposed, and the cage is disposed on both axial sides of the pockets for holding the plurality of balls. An annular portion is formed, and the annular portion has one of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring as a guide surface, and is positioned at a position facing the intersection edge portion of the guide surface and the seal receiving groove portion. A concave groove that avoids contact with the intersection edge is formed in the circumferential direction.

[0014] Further, a spindle turning device for a machine tool according to claim 3 is characterized in that the spindle turning ball bearing according to claim 1 or 2 is provided in a spindle turning portion for turning the spindle. Furthermore, the ball bearing for the spindle turning part according to claim 4 is used for the spindle turning part of the machine tool, and a large number of balls are arranged between the outer ring raceway groove and the inner ring raceway groove in a freely rolling manner. The double-row ball bearing is characterized in that the cross-sectional dimension ratio (B2 / H2) between the axial sectional width B2 and the radial sectional height H2 is (B2ZH2) <1.2.

[0015] Still further, a spindle turning device for a machine tool according to claim 5 is the spindle according to claim 4. The ball bearing for the turning part is provided in a spindle turning part for turning the spindle. In the invention according to claim 1, for example, referring to FIG. 3, a single row in which a large number of balls 103 are rotatably arranged between the raceway groove 101a of the outer ring 101 and the raceway groove 102a of the inner ring 102. In the ball bearing 100, the axial sectional width B and the radial sectional height H (= (outer ring outer diameter D—inner ring inner diameter d) Z 2) have a sectional dimension ratio (BZH) of (BZH) <0.63. .

Here, the reason why the cross-sectional dimension ratio (BZH) in the invention according to claim 1 is set to (BZH) 0.66 is as follows.

27 and 28 show the standard thin ball bearings (bearing inner diameter: Φ 203.2 mm, bearing outer diameter: φ 254 mm, bearing width: 25.4 mm, cross-sectional dimension ratio ( BZH) = 1) as a reference, when the bearing inner diameter is changed without changing the bearing outer diameter and bearing width (that is, when the value of (BZH) is changed), the inner and outer ring rings are deformed in the radial direction. The comparison results of the characteristics (see Fig. 25: inner ring shown as an example) and the radial second moment of inertia I (see Fig. 26): I = bh Vl2) are shown.

[0017] According to Figs. 27 and 28, when (B / H) = less than 0.63, the change in the gradient of increase in the stiffness is prominent. That is, the increase in the secondary moment I of the cross section becomes significant, and the decrease in the deformation amount of the inner and outer ring in the radial direction becomes saturated.

Therefore, according to the present invention, it is possible to prevent bearing deformation due to processing force during lathe machining and grinding during inner and outer ring production, which is a problem with conventional ultra-thin bearings, and bearing accuracy such as roundness and uneven thickness Can be improved.

[0018] In addition, when assembled in a shaft or nosing (especially when assembled by clearance fitting with the shaft or housing), deformation of the inner and outer rings when the bearing is fixed with an inner ring retainer or outer ring retainer ( In particular, the deterioration of roundness) can be suppressed, and in addition to poor torque and rotational accuracy caused by deformation, problems such as increased heat generation, wear, and seizure can be prevented.

In other words, compared to the ultra-thin ball bearings used in the past, it is possible to achieve both space saving and high accuracy.

[0019] FIG. 29 is a comparison data of the relative inclination angles of the inner and outer rings when a moment load is applied to each of the single row product of the present invention and the cross roller bearing.

Here, the main dimensions of the measuring bearing are Invention product:

Inner ring inner diameter: φ 170

Outer ring outer diameter: Φ 215

Single unit width: 13.5mm

Rolling element pitch circle diameter: φ 192.5

Contact angle 35.

(B / H = 0. 60)

Cross roller bearing:

Inner ring inner diameter: φ 130

Outer ring outer diameter: φ 230

Thread length: 30mm

Rolling element pitch circle diameter: φ 189.7

It is.

As is apparent from FIG. 29, the product of the present invention is compared to the cross roller bearing for both the product of the present invention and the cross roller bearing in which the pitch circle diameters of the rolling elements are substantially the same, based on the moment rigidity comparison data. In addition to the above experiments, after incorporating the product of the present invention and the cross roller bearing into the shaft and nosing, the motor (belt When the product of the present invention was rotated at a low speed by driving), the rotating force caused by torque fluctuation was actually confirmed in the case of the cross roller bearing.

On the other hand, the dimension series defined by the International Organization for Standardization (ISO) is 18 (eg 6820), 19 (eg 6924), 10 (eg 6028), 02 (eg 7224A), 03 (eg 7322A) For standard ball bearings, the inner diameter of the bearing is φ5mn! For ~ 500mm, the above-mentioned cross-sectional dimension ratio (BZH) is set to 0.63 ~: L17.

Therefore, the narrowest ball bearing of the conventional standard single row ball bearing is set by setting the cross sectional dimension ratio (BZH) of these ball bearings to the maximum value of 1.17, approximately 1Z 2 times, that is, less than 0.63. Narrower and within the axial space of conventional standard single row ball bearings, claim 1 Can be arranged in combination with two rows of ball bearings.

[0022] For example, if the sectional dimension ratio (BZH) of a conventional ball bearing is (BZH) = 0.9, the sectional dimension ratio (BZH) of the bearing of the present invention is (BZH) = 0.45. Good. In the case of this example, it is not necessary for the two ball bearings to be combined to have the same cross-sectional dimension ratio (BZH). For example, one may be 0.50 and the other may be 0.40.

In single-row ball bearings, it is difficult to apply preload or moment load in one row, but by combining multiple rows of two or more rows, radial load, axial load and moment load can be reduced. It becomes possible to load.

[0023] Further, since each ball always contacts the raceway groove of the inner and outer rings at two points, an increase in torque due to a large spin of the ball can be suppressed as in a four-point contact ball bearing. Compared to two-row combined tapered roller bearings, cross-roller bearings have lower rolling resistance and can achieve lower torque.

Furthermore, since the width dimension is about half that of the conventional standard single row ball bearing, the ball diameter is also about half that of the conventional ball bearing, but conversely the number of balls per row increases and the bearing rigidity is reduced. Increased compared to conventional ball bearings. In addition, when used in the spindle turning part of a machine tool, since it is a rocking rotation condition, rolling fatigue life time is a problem in practice even if the load capacity of the bearing is reduced by reducing the ball diameter. Never become.

[0024] In the invention according to claim 2, in the single row ball bearing, at least one end face of each of the outer ring and the inner ring is formed with a seal accommodating groove, and an annular seal body is disposed in each of the seal accommodating grooves. When the cage that positions many balls in the circumferential direction is installed, either the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring formed on both sides in the axial direction of the pocket that holds the many balls of the cage Since the concave groove portion is formed in the circumferential direction at the position facing the intersection edge portion between the guide surface and the seal receiving groove portion in the annular portion having one of the guide surfaces as described above, the narrow shape as described above. Even in the case of a bearing, it is possible to prevent wear of the annular portion due to contact with the edge by avoiding contact with the edge where the annular portion of the cage contacts the intersection edge portion by the concave groove portion.

[0025] In the invention according to claim 4, with reference to FIG. 21, for example, a large number of balls are arranged between the double row raceway grooves 20la, 201b of the outer ring 201 and the double row raceway grooves 202a, 202b of the inner ring 202. 203 can roll freely In the double-row ball bearing 200 disposed in the axial direction, the sectional dimension ratio (B2ZH2) between the axial sectional width B2 and the radial sectional height H 2 (= (outer ring outer diameter D2—inner ring inner diameter d2) / 2) is (B2ZH2) <1. 2!

By setting the cross-sectional dimension ratio (B2ZH2) as described above for a double row ball bearing, the conventional standard single unit is the same as when combining single row narrow ball bearings according to claim 1 in two rows. The double row ball bearing according to claim 4 can be arranged in the axial width space of the row ball bearing, and it is also possible to apply a preload or apply a moment load. Other operational effects are the same as those obtained when the single-row narrow ball bearing according to claim 1 is combined in two rows.

FIG. 30 is a comparison of calculated moment stiffness of various bearings. For the same size (calculation example is equivalent to bearing name 7906A (contact angle 30 °) and the inner and outer diameter dimensions are the same: inner ring inner diameter φ 30mm, outer ring outer diameter φ 47mm), the width of the single row according to claim 1 Narrow anguilla ball bearings (contact angle 30 °: calculation example of total ball bearings) are combined in two rows, and the invention examples A to E in which the inner and outer ring raceway radius of curvature are changed are all cross roller bearings, standard The moment stiffness is larger than the two-row combined angular contact ball bearings and four-point contact ball bearings. For example, the invention example B can hold moment rigidity 2.4 times that of a cross roller bearing, 1.9 times that of a standard two-row combination anguilla ball bearing, and 3.3 times that of a 4-point contact ball bearing. It is.

[0027] Each design preload clearance is -0.001mm for the examples A to E of the present invention, standard two-row combination anguilla ball bearing and four-point contact ball bearing, and -0.001mm for the cross roller bearing. (When using a cross roller bearing with a preload clearance smaller than -0.001 mm, the torque may be excessive and may be unusable in practice).

The appropriate ball diameter of the narrow ball bearing according to the present invention varies depending on whether or not a seal or the like is mounted, but in order to increase rigidity, if the ball diameter is extremely reduced, the ball and inner and outer ring raceway grooves and Since the surface pressure between the contact parts increases and the pressure scar resistance decreases, the bearing width (B) or (B2Z2) is preferably 30% to 90%.

[0028] Furthermore, when the present invention is applied to an anguilla ball bearing, the contact angle of the bearing is preferably within a range of approximately 10 to 60 ° of force selected according to required rigidity (for example, moment rigidity) and required torque. Furthermore, according to the direction and magnitude of the load, the contact angle of each combined single row bearing may be changed as necessary, or, in the case of a double row bearing, the contact angle between each row may be changed! /ヽ.

Furthermore, the radius of curvature of the inner and outer ring raceway grooves depends on the required rigidity and torque characteristics.

-60% Da (Da: ball diameter), preferably 52-56% Da, more preferably about 52-54% Da. Further, the radius of curvature of each raceway groove of the inner and outer rings may not be the same, or may be different between each row of the double row bearings between the single row bearings to be combined.

[0029] According to the present invention, in the spindle turning ball bearing used for the spindle turning portion of the machine tool, in the case of a single row ball bearing, the axial sectional width B and the radial sectional height H are Section ratio (B

ZH) is set to (BZH) <0.63, and in the case of a double row ball bearing, the sectional ratio (B2 / H2) between the axial sectional width B2 and the radial sectional height H2 is (B2ZH2) <1.2 In addition to being able to receive radial load, axial load in both directions, and moment load, high accuracy (high rotational accuracy), high rigidity, low torque and low heat generation can be achieved. As a result, it is possible to achieve further space saving. Further, by configuring the main spindle turning device by applying the main spindle turning portion ball bearing having the above effect to the main spindle turning portion, the main spindle turning device itself can also save space.

Brief Description of Drawings

FIG. 1 is a side view with a cross section of a main part showing a spindle turning device for a machine tool according to a first embodiment of the present invention (corresponding to claim 1 or 3).

FIG. 2 is a side view with a cross section of the main part showing a modification of the main spindle turning device of the machine tool according to the first embodiment (corresponding to claim 1 or 3) of the present invention.

FIG. 3 is a cross-sectional view of a single row anguilla ball bearing showing a first embodiment of a ball bearing for a spindle turning part according to the present invention.

FIG. 4 is a cross-sectional view of a principal part showing a state in which two rows of single row ball bearings of FIG. 3 are combined.

FIG. 5 is a cross-sectional view of an essential part showing a state in which two rows of single row ball bearings, which are another embodiment of the first embodiment of the present invention, are combined.

FIG. 6 is a cross-sectional view of an essential part showing a state in which two rows of single row ball bearings of FIG. 3 and single row ball bearings according to another embodiment are combined.

[Fig. 7] Two-row combination of single row ball bearings, which is another embodiment of the first embodiment of the present invention. It is principal part sectional drawing which shows the state.

[8] FIG. 8 is a cross-sectional view of an essential part for explaining a single row ball bearing which is another embodiment of the first embodiment of the present invention.

[9] FIG. 9 is a cross-sectional view of the main part showing a state in which three rows of single row ball bearings of FIG.

FIG. 10 is a cross-sectional view of a principal part showing a state in which four rows of single row ball bearings of FIG. 3 are combined.

[11] FIG. 11 is a cross-sectional view of an essential part showing a state in which the single row ball bearing of FIG. 3 is combined in a two-row front combination.

[12] FIG. 12 is a cross-sectional view of an essential part showing a state in which two rows of single row ball bearings which are other embodiments of the first embodiment of the present invention are combined.

13] A sectional view taken along the radial direction of the cage.

[14] FIG. 14 is a partial perspective view of the cage when the radial inner force is also seen.

FIG. 15 is a view seen from the direction of arrow B in FIG.

FIG. 16 (a) is a view as seen from the direction of arrow A in FIG. 13, and FIG. 16 (b) is a view showing a modification of (a). FIG. 17 is a cross-sectional view of an essential part for explaining a single-row ball bearing for a spindle turning part of a machine tool, which is an example of a modification (corresponding to claim 2) of the first embodiment of the present invention.

18] A main portion sectional view for explaining a single row ball bearing for a spindle turning portion of a machine tool.

FIG. 19 is a cross-sectional view of an essential part for explaining a modification of the single-row ball bearing for the spindle turning part of the machine tool.

FIG. 20 is a cross-sectional view of an essential part for explaining a single-row ball bearing for a main spindle turning part of a machine tool, which is an example of another modified example of the first embodiment of the present invention.

FIG. 21 is a cross-sectional view of an essential part for explaining a double-row ball bearing for a spindle turning part of a machine tool, which is an example of an embodiment in a second embodiment (corresponding to claim 4 or 5) of the present invention. FIG. 22 is a cross-sectional view of an essential part for explaining a double row ball bearing which is another embodiment of the second embodiment of the present invention.

FIG. 23 is a cross-sectional view of an essential part for explaining a double-row ball bearing which is another embodiment of the second embodiment of the present invention.

FIG. 24 is a cross-sectional view of an essential part for explaining a double-row ball bearing which is another embodiment of the second embodiment of the present invention. FIG. 25 is an explanatory diagram for explaining the amount of deformation in the radial direction of the inner ring.

[26] FIG. 26 is an explanatory diagram for explaining a method of calculating a cross-sectional secondary moment of the inner ring.

FIG. 27 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the amount of deformation of the inner and outer rings in the radial direction.

FIG. 28 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I.

FIG. 29 is a graph showing a comparison of moment stiffness between the product of the present invention and a cross roller bearing. [30] FIG. 30 is a graph showing a comparison of calculated moment stiffness in various bearings.

FIG. 31 is a cross-sectional view of a principal part of a cross roller bearing.

FIG. 32 is a cross-sectional view of a principal part of a four-point contact ball bearing.

FIG. 33 is a cross-sectional view of a main part of a conventional two-row combination anguilla ball bearing.

FIG. 34 is a cross-sectional view of a main part of a conventional two-row combination anguilla ball bearing with a very thin cross section. [35] FIG. 35 is a cross-sectional view showing a state in which a conventional double-row combination anguilla ball bearing with an ultra-thin wall section is mounted on a shaft.

FIG. 36 is a cross-sectional view of a main part of a conventional two-row combined tapered roller bearing.

圆 37] An explanatory view showing a conventional anguilla ball bearing.

FIG. 38 is a cross-sectional view of an essential part for explaining a single-row angular contact ball bearing which is an example of the first embodiment in the third embodiment of the present invention.

FIG. 39 is a cross-sectional view of the principal part showing a state in which two rows of single row anguilla ball bearings of FIG. 38 are combined.

FIG. 40 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the amount of deformation of the inner and outer rings in the radial direction.

FIG. 41 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I.圆 42] An explanatory diagram for explaining the amount of deformation of the inner ring in the radial direction.

[43] FIG. 43 is an explanatory diagram for explaining a method of calculating a cross-sectional secondary moment of the inner ring.

FIG. 44 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the amount of deformation of the inner and outer rings in the radial direction.

FIG. 45 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I. [46] It is a graph showing a comparison of calculated moment stiffness in various bearings. FIG. 47 is an essential part cross-sectional view for explaining a single-row anguilla ball bearing of the first embodiment in the third embodiment.

FIG. 48 is a cross-sectional view of an essential part for explaining the single-row anguilla ball bearing of the first embodiment in the third embodiment of the present invention.

FIG. 49 is a cross-sectional view of a principal part for explaining a modification of the single row anguilla ball bearing of the first embodiment in the third embodiment of the present invention.

FIG. 50 is a cross-sectional view of an essential part for explaining a single-row angular ball bearing according to another modification of the first embodiment in the third embodiment of the present invention.

[51] FIG. 51 is a cross-sectional view of a main part showing a state in which two rows of single row ball bearings showing another example of the single row anguilla ball bearing of the first embodiment in the third embodiment of the present invention are combined.

[52] FIG. 52 is a cross-sectional view of the cage along the radial direction.

[53] FIG. 53 is a partial perspective view of the cage as seen from the radially inner side.

[54] FIG. 54 is an essential part cross-sectional view for describing a double-row anguilla ball bearing according to a second embodiment of the third embodiment of the present invention.

FIG. 55 is a cross-sectional view showing a conventional deep groove ball bearing.

FIG. 56 is a perspective view showing the retainer of FIG. 55.

FIG. 57 is a cross-sectional view taken along the line BB in FIG. 55.

FIG. 58 is a cross-sectional view taken along the line AA in FIG. 55.

[59] FIG. 59 is a cross-sectional view showing a conventional angular contact ball bearing.

FIG. 60 is a side view showing the retainer of FIG. 59.

FIG. 61 is a cross-sectional view of an essential part for explaining a combination ball bearing as a back combination which is an example of the first embodiment in the fourth embodiment of the present invention.

FIG. 62 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the amount of deformation of the inner and outer rings in the radial direction.

FIG. 63 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I.

FIG. 64 is an explanatory diagram for explaining the amount of deformation in the radial direction of the inner ring.

[65] FIG. 65 is an explanatory diagram for explaining a method of calculating a sectional second moment of the inner ring.

FIG. 66 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the amount of deformation of the inner and outer rings in the radial direction. is there.

FIG. 67 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I.

FIG. 68 is a graph showing a comparison of calculated moment stiffness for various bearings.

FIG. 69 is a cross-sectional view taken along the radial direction of the cage.

FIG. 70 is a partial perspective view of the cage as seen from the radially inner side.

FIG. 71 is an arrow view seen from the arrow Y direction of FIG. 69.

FIG. 72 is a cross-sectional view taken along the line ZZ in FIG. 69.

FIG. 73 is an explanatory diagram for explaining the operation when the cage is moved in the axial direction.

74 (a) is an arrow view showing the force in the direction of arrow X in FIG. 69, and (b) is an arrow view showing a modification of (a).

FIG. 75 is an essential part cross-sectional view showing a state in which grease is enclosed in FIG. 61.

FIG. 76 is a cross-sectional view of relevant parts showing a combined bearing in front combination.

FIG. 77 is a cross-sectional view of a principal part showing another example of an annular seal body.

FIG. 78 is a cross-sectional view of an essential part for explaining a double-row angular contact ball bearing which is an example of a fifth embodiment in the fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0031] Embodiments in the first embodiment of the present invention will be described below with reference to Figs.

FIG. 1 is a side view in cross section of a main portion showing a first embodiment (corresponding to claim 1 or 3) when the spindle turning device of a machine tool according to the present invention is applied to, for example, a 5-axis machining center. It is.

In the figure, 30 is a spindle turning device for a machine tool. A base 31 fixed to a fixed part of the machining center, a turning base 32 rotatably supported by the base 31, and this turning base And a main spindle body 33 attached to 32.

[0032] The base 31 has a housing recess 34 for housing a swivel pedestal 32 in which the central force on the left end surface is also recessed on the right side. The swivel pedestal 32 is a ball bearing for a main shaft swivel unit according to the present invention. It is supported rotatably via 35.

Here, the swivel base 32 forms a flat mounting surface 36 at the left end opposite the left end surface of the base 31. A disc portion 37 formed, a step portion 38 that protrudes from the right end of the disc portion 37 and holds the inner ring of the main shaft turning portion ball bearing 35 and a step portion 40 that fits and holds the worm wheel 39, The central right end force also has a protrusion 42 formed with a recess 41 to reduce the weight to the left.

[0033] Then, in a state where the inner ring of the main shaft turning part ball bearing 35 is engaged with the step part 38, the inner ring presser 43 formed integrally with the worm wheel 39 is tightened with the bolt 44, whereby the step part 38 is fixed. The inner ring of the spindle bearing ball bearing 35 is fixed.

On the other hand, the outer ring of the spindle turning ball bearing 35 is fitted into a step 45 formed in the receiving recess 34 of the base 31, and the outer ring presser 46 disposed on the left end surface side of the base 31 is turned, for example. The pedestal 32 is fixed to the base 31 by bolting with bolts 47 inserted through through holes (not shown) formed in the disc portion 37 of the base 32.

[0034] The worm wheel 39 is coupled with a worm 48 coupled to a rotational drive source such as a motor. By rotating the worm 48, the swivel base 32 is attached to a tool body of a spindle body 33 described later, for example. When the surface is set to 0 ° vertically downward, the main spindle body 33 is swung (oscillated) about ± 100 ° in the longitudinal direction.

Further, the main spindle body 33 is integrated with a main spindle 52 equipped with a rotation drive source for rotating a tool with a tool mounting surface 51 for attaching a tool (not shown) such as an end mill or a drill, and a side surface of the main spindle 52 integrally. And a mounting plate portion 53 bolted to the mounting surface 36 of the disc portion 37 of the formed swivel base 32.

Next, the operation of the first embodiment will be described.

Now, for example, as shown in FIG. 1, with the spindle body 33 positioned with the tool mounting surface 51 positioned vertically downward 0 °, a tool such as an end mill or a drill is mounted on the tool mounting surface 51 of the spindle 52. Thus, cutting can be performed as a vertical machining center by moving the jig and workpiece (workpiece) relative to each other while being driven to rotate at high speed by a built-in rotation drive source.

[0036] After this cutting process is completed, the main shaft body 33 is moved forward by rotating the swivel pedestal 32 by + 90 ° by rotating the worm seat 32 forward by rotating the worm 48 forward, for example, by a rotational drive source (not shown). Turn the tool 90 ° to bring the tool to the front. By moving the workpiece and the workpiece (workpiece) relative to each other, cutting can be performed as a horizontal machining center.

Similarly, the worm 48 is driven in the reverse direction by the rotation drive source, and the swivel base, for example, the swivel base 32 and the main spindle body 33 are rotated 90 ° rearward to relatively move the power tool and the work material (workpiece). As a result, cutting can be performed as a horizontal machining center.

[0037] In this way, by applying the spindle turning ball bearing 35 according to the present invention to the spindle turning portion of the spindle turning device 30, the spindle turning ball bearing 35 has both a radial load and a bidirectional direction, as will be described later. As well as being able to receive the axial load and moment load, it is possible to achieve higher accuracy (higher rotational accuracy), higher rigidity, lower torque and lower heat generation, and further space saving Therefore, the spindle turning device 30 itself can also save space.

In the first embodiment, the case where the swivel base 32 is rotationally driven by the worm gear has been described. However, the invention is not limited to this, and the rotational base 32 is rotationally driven by applying another bevel gear mechanism or other gear mechanism. Further, as shown in FIG. 2, the worm wheel 39 and the worm 48 are omitted, and the stator 61 disposed on the inner peripheral surface of the housing recess 34 of the base 31 and the swivel opposite thereto are arranged. The turning base 32 may be directly driven to turn by a direct motor 63 composed of a rotor 62 disposed on the outer peripheral surface of the projecting portion 42 of the base 32. In the case of FIG. 2, it is preferable to apply a ball bearing with a single-side seal and cage shown in FIG. In addition, the swivel base 32 includes a base 64 that holds the main spindle turning ball bearing 35 and the rotor 62, and a mounting plate 65 that also serves as an inner ring presser of the main spindle turning ball bearing 35 that is bolted to the base 64. It is configured.

Here, the direct motor 63 is not limited to the configuration of the outer rotor type shown in FIG. 2, but a rotor is disposed on the inner peripheral surface of the recess 41 of the protrusion 42, and a stator is disposed on the inner side of the rotor. An inner rotor type may be used.

In the first embodiment, the case where the swivel base 32 is rotatably supported in the housing recess 34 formed in the base 31 has been described. However, the present invention is not limited to this. The swivel base 32 is rotated through the ball bearing 35 for the main spindle revolving unit according to the present invention. Let's support it freely.

[0039] Furthermore, in the first embodiment, the case where the present invention is applied to a machining center has been described. However, the present invention is not limited to this, and is not limited to lathes, milling machines, grinding machines, lapping machines, etc. The present invention can be applied to an arbitrary composite type machine tool provided with a spindle turning device for turning the spindle to add a center function.

Furthermore, the main spindle turning device 30 is not limited to the above-described configuration, and any configuration may be adopted as long as the main spindle body 33 is supported via the main spindle turning portion ball bearing. it can.

[0040] Next, a specific example of the ball bearing 35 for the spindle turning portion according to the present invention applied to the spindle turning portion of the spindle turning device 30 will be described.

For the ball bearing 35 for the spindle turning part, (a) the spindle body 33 installed on the turning pedestal 32 of the spindle turning device 30 is rotated with high accuracy (runout accuracy), and (b) the spindle body 33 is driven with low torque. (C) It is required to reduce the displacement of the entire spindle body with respect to the load during machining (high rigidity). In addition to the moment load due to the weight of the spindle related parts and the inertia load generated during turning acceleration / deceleration, the radial bearing, axial load and moment load generated according to the machining conditions are applied to the ball bearing 35 for the spindle turning part. It can act alone or these loads can act in combination.

[0041] FIG. 3 shows a first embodiment (corresponding to claim 1) of a ball bearing for a spindle turning part according to the present invention. The main shaft turning part ball bearing (single row ball bearing) 100 shown in the figure has a large number of balls 103 rotatably arranged between a raceway groove 101a of the outer ring 101 and a raceway groove 102a of the inner ring 102. In the single-row all-round angular contact ball bearing 100, the sectional dimension ratio (BZH) between the axial sectional width B and the radial sectional height H (= (outer ring outer diameter D—inner ring inner diameter d) / 2) is expressed as (BZH ) <0. 63 The reason for this has been described in detail with reference to FIG. 29 in the means for solving the above-mentioned problem, and is not described here.

[0042] Here, in this embodiment, as shown in Fig. 4, an anguilla ball bearing 100 is used as a two-row rear combination, and is replaced with a 7940A (contact angle 30 °) two-row combination angio ball bearing. take.

7940A Anguilla ball bearing has an inner ring inner diameter d: 0> 200mm, outer ring outer diameter D: Φ 280mm, Axial cross-sectional width (bearing unit width) B is 38 mm, so the cross-sectional dimension ratio (BZH) is 0.95. Therefore, in the angular contact ball bearing 100 of this embodiment, the cross-sectional dimension ratio (BZH) = 0.475 (the inner ring inner diameter and outer ring outer diameter remain the same, and the axial sectional width (bearing unit width) B is 19 mm). Yes. As a result, radial load, axial load in both directions, and moment load can be received, as well as high accuracy (high rotation accuracy), high rigidity, low torque and low heat generation. At the same time, 1Z2 can be saved in the axial dimension.

[0043] Of course, if necessary, even if the cross-sectional dimension ratio (BZH) of the angiular ball bearing 100 is set to less than 0.475 or more than 0.475 (however, (BZH) is 0.63). It does n’t turn. Incidentally, the contact angle of the anguilla ball bearing 100 is, for example, 30 °.

In this embodiment, the pitch circle diameter of the balls 103 is as shown in the following formula (1). If you want to increase the moment stiffness by increasing the number of balls per row of force bearings, the following formula (2) The pitch circle diameter of the ball 103 can be shifted to the outer ring side to create the structure shown in Fig. 5! If necessary, the pitch circle diameter of the ball 103 can be reversed by using the following formula (3). May be shifted to the inner ring 102 side (not shown).

Ball pitch circle diameter = (inner ring inner diameter + outer ring outer diameter) Z2-(1)

Ball pitch circle diameter> (inner ring inner diameter + outer ring outer diameter) Z2 --- (2)

Ball pitch diameter (inner ring inner diameter + outer ring outer diameter) Z2 --- (3)

If necessary, as shown in FIG. 6, the ball pitch circle diameters of the combined left and right ball bearings do not have to be the same value, and the diameters of the balls 103 in the combined left and right ball bearings do not have to be the same value. May be. If the ball bearings have the same cross-sectional dimension ratio (BZH), for example, (BZH) = 0.35 for the smaller ball diameter and (BZH) = 0.60 for the larger ball diameter. I do not care. Further, the axial pitch of the ball 103 may not be centered in the axial direction, and the axial pitch of the ball 103 may be shifted in the axial direction in order to secure the distance between the action points of the seal and the cage, or to install the ball. Yo ...

[0044] FIG. 7 shows a back row combination of an anguilla ball bearing 100 having an annular seal body 104 attached to one end in the axial direction.

Two rows of anguilla ball bearings 100 with an annular seal 104 attached to one end in the axial direction After being combined and mounted on a machine (with the seal mounting surface facing outward), it is possible to prevent foreign matter and dust from entering the bearing and leakage of the enclosed grease to the outside while using the bearing. is there. In this embodiment, the annular seal body 104 is a non-contact type (non-contact with the inner ring 102) inserted into the seal groove 104a of the outer ring 101, and a reinforcing rubber seal (for example, -tolyl rubber'acrylic) of the metal core 105. (Rubber or fluororubber) 10 6 and an annular seal 104 is attached only on the side opposite to the combined end face to save space.

FIG. 8 shows an anguilla ball bearing 100 in which annular seal bodies 104 are mounted at both ends in the axial direction.

After mounting an anguillar ball bearing 100 with annular seals 104 on both ends in the axial direction to a machine, etc., while using the bearing, it prevents foreign matter and dust from entering the bearing while handling the bearing. Even when it is installed in the shaft housing, it is possible to prevent foreign matter and dust from entering and leakage of the enclosed grease to the outside. As for the combination, in order to increase the moment stiffness in two rows, the back side combination (the contact angle is in the direction of the letter C in Fig. 4 etc.) that can take the distance of the moment's action point is adopted. Is desired.

[0046] If more rigidity is required, a multi-row combination of three or more rows may be used as shown in FIGS. 9 and 10, and for some reason (for example, misalignment can be avoided when incorporating a bearing). If you want to reduce the moment rigidity, for example, if you want to reduce the internal load load of the bearing as much as possible), as shown in Fig. 11, the front combination (contact angle direction is reversed) may be used. .

Furthermore, in order to apply a moment load or both axial loads, it is necessary to use two or more rows of combined bearings. It doesn't work even if you use it.

[0047] In the present embodiment, the angular ball bearing is used, but other ball bearings such as a deep groove ball bearing may be used. The annular seal body may be a contact-type metal core reinforced rubber seal (for example, -tolyl rubber, acrylic rubber or fluororubber), which is not the non-contact type shown in FIGS. You can also use a metal shield plate that is crimped into the seal groove. Also, insert the annular seal body by pushing it into the seal groove on the inner ring 102 side. Or it may be attached by caulking! ヽ (structure that contacts or does not contact the outer ring).

[0048] The material of the inner ring 102, the outer ring 101, and the ball 103 is a force that is a bearing steel (eg, SUJ2, SUJ3, etc.) under standard use conditions. Depending on the usage environment, a stainless steel material (for example, a corrosion resistant material) Martensitic stainless steel materials such as SUS440C, austenitic stainless steel materials such as SUS304, precipitation hardened stainless steel materials such as SUS630), titanium alloys and ceramic materials (eg, Si N, SiC, Al 2 O, ZrO, etc.) May be adopted.

3 4 2 3 2

[0049] The lubrication method is not particularly limited, and in a general use environment, a mineral oil-based grease or a synthetic oil-based grease is used.

Grease and oil (for example, lithium-based, urea-based, etc.) can be used. For high-temperature environment applications, fluorine-based grease or fluorine-based oil, or fluorine lubricant, solid lubricant such as MoS

2

Can be used.

FIG. 12 shows an anguilla ball equipped with an annular seal body 104 at one end in the axial direction (the end opposite to the end surface on the combination side) and a retainer 110 that holds the ball 103 in a rollable manner. This is a combination of 100 bearings and 2 backs.

For example, as shown in FIGS. 13 to 16 (a), the cage 110 includes an annular portion 111 and a plurality of axial directions at substantially equal intervals in the circumferential direction at one end portion of the annular portion 111. And adopting a flexible crown-shaped cage having a column portion 112 projecting from the column portion 112 and a pocket portion 113 formed between the column portions 112 to hold the ball 103 so as to be able to roll in the circumferential direction. Yes. The material of the cage 110 is, for example, a synthetic resin material such as polyamide, polyacetal, or polyphenylene sulfide, and a material in which a reinforcing material such as glass fiber or carbon fiber is mixed into the synthetic resin material is used as necessary.

[0051] In this embodiment, in order to increase the load capacity and rigidity of the bearing, the circumferential pitch between adjacent balls 103 is made as small as possible and the number of balls is increased as much as possible. Further, the axial pitch of the balls 103 is shifted to the opposite side of the end face on the combination side as much as possible (Fig. 12: X> X)

1 2 The ring part 111 of the cage 110 is arranged so as to be on the end face side of the bearing combination, so that the distance between the operating points for increasing the moment rigidity can be increased.

In the case of a full ball bearing, the ball pitch in the axial direction is not the center of the width in the same way as necessary, such as whether or not an annular seal body is attached (bearing end face side or opposite). To the side) does not work. [0052] A bearing with a cage is used for all ball bearings under conditions where the revolution speed is likely to vary due to changes in the contact angle of each ball, such as the condition of continuous rotation in one direction and the application of a large moment load. It is more effective in terms of low torque and low heat generation in applications where contact between balls or clogging is likely to occur when used.

Furthermore, in this embodiment, if the entrance portion of the pocket portion 113 is slightly smaller than the ball diameter and a pulling force (batching allowance) is provided, the ball 103 will not drop out when assembled into the inner ring 102 and the outer ring 101. Is easy to assemble.

[0053] The shape of the cage is not limited to this embodiment, and any type other than the separator-type cage disposed between the balls 103 may be used. The material may also be a metal material that is not a synthetic resin material.

FIG. 16 (b) is a crown-shaped cage having the same basic structure as FIG. 16 (a), but the adjacent pocket portions 113 are cut in advance at least at one location in the circumferential direction of the annular portion 111. And it is set as the structure which gave the predetermined clearance gap between each cut surface.

[0054] By adopting such a structure, the difference in the thermal expansion coefficient between the cage and the inner and outer rings and the variation in the dimensional accuracy and roundness of the cage (particularly in the case of an embodiment with a large bearing size). Therefore, even if the rolling element pitch circle diameter deviates from the pitch circle diameter of the cage, the radial flexibility due to the cantilever shape and the elastic deformation in the circumferential direction due to the gap between the cut surfaces ( (Flexibility in the circumferential direction), the cushioning force between the ball 103 and the pocket 113 is buffered to prevent the cage from being damaged or worn, and the ball 103 and the pocket 113 Torque unevenness and heat generation due to sliding contact resistance can be further reduced.

[0055] In addition, since the ball bearing for the spindle turning part of the present invention is structurally small in diameter, the thickness of the annular part 111 of the cage in the radial direction cannot be increased (also understood from FIG. 12). Therefore, the cage needs to be positioned with an appropriate gap in the gap between the outer diameter of the inner ring and the inner diameter of the outer ring. The gap between the outer diameter of the inner ring and the inner diameter of the outer ring is approximately the same as the ball diameter. Furthermore, due to the proportional relationship, it is narrow), and due to the narrow structure, the axial gap and the axial thickness must be reduced. For this reason, since the circular part of the cage is extremely small compared to a standard size bearing, the dimensional accuracy such as roundness is given <<, so the cage structure with the annular part 111 as shown in Fig. 16 (b) is In particular, with respect to the above-mentioned cage damage and wear prevention effect and torque unevenness and heat generation reduction An effect is obtained.

[0056] In addition, the intended application is swivel rotation, and the centrifugal force is not continuously applied to the cage. Therefore, when the present invention is applied to these uses, even if the cage structure as shown in FIG. If necessary, the cut portion of the annular part 111 may be two or more places in the circumferential direction. In this case, it is desirable that the cut points be equally divided in the circumferential direction as much as possible. In addition, when these ball bearings are applied to the spindle turning device of a machine tool, they are usually used with a preload to increase the rigidity, but there are gaps depending on the conditions or other uses. You can use it.

Furthermore, with reference to FIG. 17, a modification of the first embodiment described above (corresponding to claim 2) will be described.

In this modification, an annular seal body 120 is provided on one side of a single-row ball bearing 100 constituted by a single-row all-ball annulus ball bearing shown in FIG. 1, and a plurality of balls 103 are positioned in the circumferential direction. A vessel 130 is provided.

That is, as shown in FIG. 17, seal housing grooves 121 and 122 for housing the annular seal body 120 are disposed, for example, on one end face on the right side of the outer ring 101 and the inner ring 102.

The annular seal body 120 is constituted by a reinforced rubber seal (for example, -tolyl rubber 'acrylic rubber or fluororubber) 126 reinforced with a metal core 125 formed in an inverted L shape. The rubber seal 126 has a fitting portion 126a that fits the outer ring 101 on the outer peripheral portion, and a lip portion 126b that contacts the inner ring 102 on the inner peripheral portion.

The seal receiving groove 121 of the outer ring 101 is formed in a circumferential direction on the right end side of the inclined inner peripheral surface 101b that is connected to the raceway groove 101a of the outer ring 101, and in the circumferential direction at the bottom of the step part 121a. A shallow portion into which the fitting portion 126a of the annular seal body 120 is pushed and inserted, and a fitting concave portion 121b. Further, the seal housing groove 122 of the inner ring 102 is relatively deep on the right end side on the right side of the raceway groove 102a on the cylindrical outer peripheral surface 102b connected to the left and right ends of the raceway groove 102a of the inner ring. A shallow lip portion 126b formed on the inner peripheral surface of the annular seal body 120 formed in the circumferential direction is formed on the bottom surface of the inner surface of the cylindrical seal member 120, and a housing concave portion 122b. [0059] Furthermore, the retainer 130 has a pair of annular portions 132a and 132b extending in the axial direction with the pocket portion 131 that accommodates the ball 103 interposed therebetween, and these annular portions 132a and 132b are the inner rings 10 2. The cylindrical outer peripheral surface 102b is mounted as a guide surface.

An annular portion 132b on the side of the annular seal body 120 has an intersection edge portion 123 on the inner circumferential surface facing the intersection edge portion 123 formed at the intersection between the cylindrical outer circumferential surface 102b of the inner ring 102 and the seal housing groove 122. A concave groove 133 having a semicircular cross section that avoids contact is formed in the circumferential direction.

[0060] This cage 130 is made of a metal material such as a copper alloy manufactured by cutting, a synthetic resin material such as polyamide, polyacetal, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or glass. Manufactured with a synthetic resin material with reinforcing material added with reinforcing materials such as fiber and carbon fiber. When the cage 130 is formed of a resin material, either cutting molding or injection molding can be applied.

Thus, since the concave groove 133 is formed in the circumferential direction on the inner peripheral surface facing the intersection edge portion 123 formed on the right end side of the guide surface of the cage 130, the intersection edge portion 123 is retained. It is possible to reliably prevent contact with the inner peripheral surface of the vessel 130, while widening the width of the annular portion 132b on the annular seal body 120 side and increasing the cross-sectional area while ensuring the strength, Wear of the cage 130 can be reliably prevented.

[0061] Further, the concave groove 133 provided in a part of the guide surface can serve as a reservoir for holding a dull in the case of grease lubrication, and in addition, is located in the vicinity of the guide surface. In addition, there is an effect of appropriately supplying lubricating oil to the guide surface, and the wear resistance can be maintained for a long time from the viewpoint of the lubrication characteristics. This effect becomes more conspicuous when concave grooves 133 and 134 are formed in both annular portions 132a and 132b as shown in FIG. 20 described later.

Normally, when the annular seal body 120 is disposed on at least one side of the ball bearing 100, the force that uses the inner diameter surface of the outer ring 101 and the outer diameter surface of the inner ring 102 as the guide surface of the retainer 130. Since the intersection edge portion 123 is formed at a position where the groove 122 is in contact with the groove 122, the cage 130 is worn due to the contact between the intersection edge portion 123 and the annular portion 132b of the cage 130. [0062] In order to prevent the wear of the cage 130, conventionally, when the inner ring guide is used, as shown in FIG. 18, the axial direction of the annular portion 132b on the intersection edge portion 123 side of the cage 130 It is considered that the length or width is shortened so that the annular portion 132b and the intersection edge portion 123 do not contact each other.

However, in the case of the narrow ball bearing 100 as in this embodiment, there is a problem that the width of the annular portion 132b becomes very thin and sufficient strength cannot be secured.

For this purpose, as shown in FIG. 19, it is necessary to increase the width of the annular portion 132b to ensure the strength. In this case, as described above, the inner portion of the annular portion 132b is increased. Since the circumferential surface and the intersection edge portion 123 face each other, when the cage 130 is inclined with respect to the guide-side raceway while the ball bearing 100 is rotating, the inner circumferential surface of the annular portion 132b is the intersection edge. The cage 130 will wear due to the edge hitting the part 123.

In particular, since the seal receiving grooves 121 and 122 are often heat-treated surfaces after cutting, the surface roughness is poor and burrs are likely to be formed at the intersections where they contact the cage 130. Is likely to occur.

[0064] Further, the ball bearing 100 according to the present invention has a structure in which the ball diameter is very small with respect to the ball pitch circle diameter of the bearing, and accordingly, the cross section of the annular portion 132b of the cage 130 is correspondingly reduced. And the radial strength of the cage 130 (radial strength of the annular portion 132b) is also reduced. In addition to this, the application of the ball bearing 100 according to the present invention tends to tilt the bearing because a large moment load is easily applied during rotation of the bearing due to its usage conditions. Therefore, due to the change in the contact angle of each ball 103, the revolution speed of each ball 103 varies, and the deformation of the cage 130 due to the tensile force between the ball 103 and the pocket 131 increases, which makes it easier to hit the edge. The contact surface pressure also increases and wear tends to progress.

However, as described above, in the present embodiment, as shown in FIG. 17, the width of the annular portion 132b on the annular seal body 120 side of the cage 130 is increased to increase the cross-sectional area. However, since the concave groove 133 is formed in a portion that may come into contact with the intersection edge 123 of the boundary between the seal housing groove 122 and the cylindrical outer peripheral surface 102b serving as the guide surface, the cage 130 is inclined. However, since a sufficient space can be secured between the intersection edge portion 123 and the concave groove portion 133, the contact between the concave groove portion 133 and the intersection edge portion 123 can be reliably prevented. Thus, wear of the cage 130 can be reliably prevented.

In the above modification, the case where the annular seal body 120 is disposed on the right side of the ball bearing 100 has been described. However, the present invention is not limited to this, and the annular seal body 120 is disposed on the left side of the ball bearing 100. It may be arranged, and furthermore, the annular seal body 120 may be arranged on both sides.

In the above modification, the case where the concave groove 133 formed in the annular portion 132b is formed in a semicircular cross section has been described. However, the present invention is not limited to this. Any shape can be used as long as it can avoid contact with the intersection edge portion 123 such as.

Furthermore, in the above-described modification, the case where the annular seal body 120 is in contact with the inner ring seal housing groove 122 has been described. However, the present invention is not limited to this and is in contact with the inner ring seal housing groove 122 shown in FIG. In addition, a non-contact rubber seal type (attached to the metal core) or a metal seal that is swaged to the outer ring seal groove can be applied.

Furthermore, in the above-described modification, the case where the guide surface of the cage 130 is the outer peripheral surface of the inner ring 102 has been described, but the inner peripheral surface of the outer ring 101 is not limited to this and is used as the guide surface. May be.

[0068] Furthermore, in the above modification, the force described in the case where the concave groove portion 133 is formed in the annular portion 132b on the annular seal body 120 side of the annular portions 132a and 132b of the cage 130. As shown in FIG. 20, the annular portion 132a opposite to the annular seal body 120 is sandwiched between the concave groove portion 133 of the annular portion 132b and the vertical surface passing through the center of each ball 103, as shown in FIG. You may make it provide the concave groove part 134 in a plane symmetrical position. As described above, when the concave groove portions are formed in the left and right annular portions 132a and 132b, the concave groove portions of the retainer 130 can be assembled from any direction without being confirmed at the time of assembly, thereby improving the assembling work. be able to.

Next, referring to FIG. 21, a double row ball bearing for a spindle turning part of a machine tool, which is an example of an embodiment of the second embodiment (corresponding to claim 4 or 5) of the present invention. Will be explained.

This double row full ball anguilla ball bearing 200 has a large number of balls 203 arranged between the double row raceway grooves 201a and 201b of the outer ring 201 and the double row raceway grooves 202a and 202b of the inner ring 202, The cross-sectional dimension ratio (B2ZH2) to the axial cross-section width B2 and radial cross-section height H2 (= (outer ring outer diameter D2—inner ring inner diameter d2) Z2) is (B2ZH2X 1.2), and the ball pitch circle diameter is This is set at the center of the height in the radial direction because the reason for this has been described in detail with reference to FIG.

Here, in this embodiment, a case where the double-row ball bearing 200 is replaced with a 7940A (contact angle 30 °) two-row combined angular ball bearing is taken as an example.

7940A has an inner ring inner diameter d: Φ 200πιπι, an outer ring outer diameter D: Φ 280 mm, an axial sectional width (bearing single body width): B is 38 mm, and therefore the sectional dimension ratio (BZH) = 0.95. Therefore, in the angular contact ball bearing 200 of this embodiment, the cross-sectional dimension ratio (B2ZH2) = 0.95 (the inner ring outer diameter and outer ring outer diameter remain the same, and the axial section width (bearing unit width): B2 is 38 mm) It is said. As a result, radial load, axial load in both directions, and moment load can be received, as well as high accuracy (high rotation accuracy), high rigidity, low torque and low heat generation. In addition, space saving of 1Z2 can be achieved in the axial dimension.

Of course, if necessary, the cross-sectional dimension ratio (B2ZH2) may be set to be less than 0.95 or more than 0.95 (however, (B2ZH2) is 1. 2). Incidentally, the contact angle of the anguilla ball bearing 200 is, for example, 30 °.

Fig. 22 shows an example in which the ball pitch circle diameter is shifted to the outer diameter side with a double-row full ball anguilla ball bearing 200 in order to increase the moment rigidity. Fig. 24 shows an example of changing the ball diameter of the row and the ball pitch circle diameter. Fig. 24 shows a double row full ball anguilla ball bearing 200 fitted with annular seals 104 at both ends in the axial direction. This is an example in which the ball pitch circle diameter is shifted to the outer diameter side.

[0072] In any of the examples, in addition to the structure of the annular seal body, the cage, and the like and whether or not it is mounted, the application example related to the structure is the same as the single row ball bearing described in the first embodiment. Further, similarly to the first embodiment, it may be used under any conditions of preload and clearance.

Next, the spindle turning part of a machine tool, which is an example of the embodiment of the third embodiment of the present invention, other machine tools, industrial machines, robots, medical equipment, semiconductor Z liquid crystal manufacturing equipment, optics, and optoelectronic equipment Especially for ball bearings An anguillare ball bearing in which a load and an axial load in both directions, especially a large moment load, acts as a load will be described. Generally, an anguilla ball bearing is not equipped with a seal like a deep groove ball bearing. Therefore, for example, as shown in FIG. 37, single row angular contact ball bearings 73A and 73B are arranged in two rows between the housing 71 and the shaft 72, and the inner ring presser 74 and the bearing which are constituted by the inner ring 73a. When the outer ring 73b is fixed with the outer ring retainer 76 while being fixed with the nut 75, the extension line L1 in the normal direction of the contact point representing the contact angle of the angular bearings 73A, 73B is only the shoulder of the inner ring 73a and the outer ring 73b. Passing through the parts 73c and 73d, the shaft 72 or the inner ring presser 74 is passed, the udging 71 or the outer ring presser 76 is passed.

[0073] When an external load is applied to the anguilla ball bearings 73A and 73B as a load, the contact portion between the rolling elements 73e, the inner ring 73a, and the outer ring 73b formed by balls interposed between the inner ring 73a and the outer ring 73b 37, the so-called rolling element load generated in the normal direction of the contact portion representing the contact angle is generated between the rolling element 73e and the inner ring 73a and the outer ring 73b in the direction between the contact parts. In particular, when the ratio of moment load is large, the rolling element load of some of the rolling elements 73e (mainly at a position opposite to 1 80 °) becomes extremely large.

[0074] In an anguilla ball bearing without a seal as shown in Fig. 37, when the contact angle is about 30 ° as shown in Fig. 37 (a), the direction of the rolling element load is an anguilla ball. Both of the bearings 73A and 73B pass through the groove 73c of the inner ring 73a and the bearing mounting portion of the shaft 72.When the contact angle is about 60 ° as shown in FIG. The direction of the rolling element load is through the shoulder 73c of the inner ring 73a in the angular ball bearing 73A and through the step 73f that serves as the inner ring presser of the shaft 72, and in the shoulder of the inner ring 73a in the angular bearing 73B. It passes through 73c, passes through the inner ring retainer 74, and reaches the bearing mounting portion of the shaft 72.

[0075] Thus, in the angular bearings 73A and 73B having no seal, the inner ring 73a and the outer ring 73b are backed up by the shaft 72 and the inner ring retainer 71 and the inner ring retainer 74 and the outer ring retainer 76 that are in contact with them. Therefore, only the shoulders 73c and 73d of the inner ring 73a and the outer ring 73b do not bear the rolling element load. Therefore, the groove shoulders 73c and 73d do not deform and support the rolling element load. Can do.

Therefore, as described in JP-A-2006-105385 (hereinafter referred to as Patent Document 3), a large number of balls are rotatably arranged between the outer ring raceway groove and the inner ring raceway groove. Was In single-row ball bearings, a seal is provided even for narrow-angle anguillar ball bearings in which the cross-sectional dimension ratio (B / H) between the axial cross-section width B and the radial cross-section height H is (BZH) <0.63 If not, bearing the rolling element load only at the shoulder of the inner ring or outer ring can support the rolling element load without deformation of the shoulder.

[0076] However, when the contact angle of the narrow anguilla ball bearing disclosed in Patent Document 3 is increased as a sealed anguilla ball bearing as shown in FIG. The extension line in the normal direction of the part passes through the groove part that accommodates the seal, the inner ring groove that is not knocked up bears the rolling element load only in the shoulder part, and the ball, inner ring, and outer ring only In addition to the elastic deformation of the contact part, elastic deformation of the groove shoulder part occurs, leading to a decrease in rigidity. In addition, when the rolling element load is large, there are unsolved problems such as breakage or chipping in the groove shoulder.

[0077] Therefore, the third embodiment of the present invention has been made paying attention to the unsolved problems of the above conventional example, and when forming a groove or the like for storing the seal, at least the inner ring and the outer ring are reduced. On the other hand, the purpose of the present invention is to provide an anguilla ball bearing that does not bear the rolling element load only at the shoulder.

In order to achieve the above object, the first embodiment of the third embodiment of the present invention is an inner ring in which a concave step having a diameter smaller than that of the inner ring groove shoulder is formed at least in a part of the circumferential direction. , And at least one of the outer rings in which a concave step portion having a diameter larger than the shoulder portion of the outer ring groove is formed at least in a part in the circumferential direction, and a large number of grooves are provided between the race grooves of the outer ring and the race grooves of the inner ring. In the narrow single-row anguilla ball bearing in which the balls of the ball are freely rollable, the normal line extending at the contact portion between the ball and the outer ring and the inner ring does not interfere with the concave step. The feature is that the contact angle is set as follows.

[0078] Further, the second embodiment of the third embodiment includes an inner ring in which a concave step portion having a diameter smaller than that of the inner ring groove shoulder is formed at least in a part of the circumferential direction, and at least the circumferential direction. At least one of the outer rings in which a concave step portion having a diameter larger than the shoulder portion of the outer ring groove is formed, and a large number of balls can freely roll between the race groove of the outer ring and the race groove of the inner ring. In the narrow double-row anguillare ball bearing disposed in the contact angle, the contact angle is set so that the normal extension line at the contact portion between the ball, the outer ring and the inner ring does not interfere with the concave stepped portion. It is characterized by.

[0079] Further, a third embodiment of the third embodiment is the same as the first or second embodiment, wherein the concave step portion is constituted by a groove into which an annular seal body is inserted and an opposing seal labyrinth portion. It has been characterized by

Furthermore, a fourth embodiment of the third embodiment is the embodiment according to any one of the first to third forces described above, wherein an annular seal is formed on the concave step portion of either the inner ring or the outer ring. The body is inserted, and the annular seal body is configured to be in contact or non-contact with the concave step portion of the inner ring and the outer ring corresponding to the inserted side. .

[0080] Here, the narrow anguilla ball bearing is a size that does not fit the standard anguilla ball bearing (78xx, 79xx, 7 Oxx, 72xx, 73xx series, etc.), that is, at least for example, a single row anguilla ball bearing In the case of a single-row angular ball bearing with a narrow cross-section dimension ratio (BZH) of (BZH) <0.63, and a double-row angular ball bearing, This is a narrow double-row annulus ball bearing in which the cross-sectional dimension ratio (B2 / H2) between the axial cross-sectional width B2 and the radial cross-sectional height H2 is (B2ZH2) <1.2.

[0081] Further, as the contact angle of the anguilla ball bearing, the height of the shoulder of the inner ring and the outer ring 'ratio of the ball diameter and the bearing width · The force that varies depending on the shape and size of the seal groove is approximately 60 ° or less, preferably 50 ° or less, more preferably 40 ° or less, but less than 20 ° is not preferable because the allowable axial load and allowable moment load decrease.

According to the third embodiment, in the case of a narrow single row anguilla ball bearing and a double row anguilla ball bearing, the extension line in the normal direction at the contact portion between the ball and the outer ring and the inner ring is the concave stepped portion. Since the contact angle is set so that it does not interfere with the bearing, it is possible to reliably prevent the rolling element load from being borne only by the shoulders of at least one of the inner ring and the outer ring, and a narrow anguilla ball bearing with a seal. In addition, the groove shoulder does not deform, and the effect of supporting the rolling element load is obtained.

Hereinafter, a first embodiment in the third embodiment will be described in detail with reference to the drawings.

FIG. 38 is a cross-sectional view of an essential part for explaining a single row ball bearing as an example of the first embodiment in the third embodiment, and FIG. 39 shows a state in which two rows of single row ball bearings of FIG. 38 are combined. It is principal part sectional drawing.

As shown in FIG. 38, a single row ball bearing 100, which is an example of the first embodiment in the third embodiment, includes a large number of balls 10 between the raceway groove 101a of the outer ring 101 and the raceway groove 102a of the inner ring 102. In the single row anguillar ball bearing 100 in which 3 is freely rotatable, the sectional dimension of the axial sectional width B and the radial sectional height H (= (outer ring outer diameter D—inner ring inner diameter d) / 2) The ratio (BZH) is set to (B / H) 0.63.

[0083] Here, in this embodiment, as shown in Fig. 39, an anguilla ball bearing 100 is used as a two-row rear combination, and is replaced with a two-row combination anguilla ball bearing of 7208A (contact angle 30 °) as an example. take.

The 7208A anguilla ball bearing has an inner ring inner diameter of 40 mm, an outer ring outer diameter of 80 mm, and an axial sectional width (bearing unit width) B of 18 mm, so the sectional dimension ratio (BZH) = 0.9. Therefore, in the angular contact ball bearing 100 of this embodiment, the cross-sectional dimension ratio (BZH) = 0.45 (the inner ring inner diameter and the outer ring outer diameter remain the same, and the axial sectional width (bearing unit width) is 9 mm). is doing. As a result, it is possible to receive radial load, axial load in both directions, and moment load, as well as to save 1Z2 in axial dimension, lower torque, and further increase rigidity.

[0084] Of course, if necessary, the cross-sectional dimension ratio (BZH) of the anguilla ball bearing 100 may be set to less than 0.45 or more than 0.45 (however, (BZH) is less than 0.63). It does n’t turn.

Thus, the reason why B / H <0.63 is as follows.

Figures 40 and 41 show the standard thin ball bearings (Bearing inner diameter: φ 3 8. lmm, Bearing outer diameter: 47.625mm, Bearing width: 4.762mm, Cross sectional dimension ratio (BZ H ) = Based on 1), the radial deformation characteristics of the inner and outer ring rings when the bearing inner diameter is changed without changing the bearing outer diameter and bearing width (ie, when the value of (BZH) is changed) (FIG. 4 2 see: the inner ring of illustration) and radial cross-sectional secondary moment I: shows the result of comparison (Figure 43 refer calculated as I = bh ^3/12), Ru.

[0085] In addition, for FIG. 44 and FIG. 45, the ultra-thin ball bearings that are used as standard (bearing inner diameter: Φ 63.5 mm, bearing outer diameter: φ 76.2 mm, bearing width: 6. 35 mm, Based on the cross-sectional dimension ratio (BZH) = 1), change the bearing inner diameter without changing the bearing outer diameter and bearing width. The results of comparing the radial deformation characteristics of the inner and outer ring rings and the radial moment of inertia I of the inner and outer rings when the value of (BZH) is changed are shown.

All bearings have (BZH) = less than 0.63, and the change in the gradient of increase in rigidity is remarkable. That is, the increase in the secondary moment I of the cross section becomes significant, and the decrease in the deformation amount of the inner and outer ring in the radial direction becomes saturated.

Therefore, in this embodiment, it is possible to prevent bearing deformation due to the processing force during lathe machining and polishing during inner and outer ring production, which is a problem with conventional ultra-thin wall bearings. The bearing accuracy can be improved.

Also, when the shaft is installed in the housing (especially when it is assembled with a shaft or housing by clearance fitting), deformation of the inner and outer rings when the bearing is fixed with inner ring retainers or outer ring retainers (especially roundness) Deterioration of torque) and poor rotation accuracy due to deformation, increased heat generation, wear and seizure, and the like can be prevented.

[0087] Note that it is difficult to apply preload or moment load to single row ball bearings in one row, but by combining multiple rows of two or more rows, radial load, axial load and And moment load can be applied.

In addition, each ball always contacts the inner and outer ring raceway grooves at two points, so that it is possible to suppress an increase in torque due to a large spin of the ball as in the case of a four-point contact ball bearing. Since the rolling resistance is lower than that of the bearing, a reduction in torque can be realized.

[0088] Furthermore, since the width dimension is about half that of the conventional standard single row ball bearing, the ball diameter is also about half that of the conventional ball bearing, but conversely, the number of balls per row increases, Bearing rigidity is increased compared to conventional ball bearings. Also, when applied to the arm joint of a turning robot, etc., since the rotation speed is mostly low, rolling fatigue life time is practical even if the load capacity of the bearing is reduced by reducing the ball diameter. There is no problem.

Other industrial machines, machine tools, robots, medical equipment, semiconductor Z liquid crystal manufacturing equipment, optics and optoelectronic equipment, etc. have a low rotation speed, and many applications are oscillating rotation. There is hardly anything.

[0089] FIG. 46 is a comparison of the calculated moment stiffness of various bearings. Same size (calculation example is equivalent to bearing name 7906A (contact angle 30 °) and the inner and outer diameters are the same: inner ring inner diameter φ 30mm For outer ring outer diameter φ 47mm), single row narrow anguillar ball bearings (contact angle 30 °: calculation example of bearing) according to claim 1 are combined in two rows, and raceway radius of curvature of inner and outer rings (Da is In the present invention examples A to E in which the ball diameter is changed, the moment rigidity is higher than that of the cross roller bearing, the standard two-row combined angular contact ball bearing and the four-point contact ball bearing. B can hold moment rigidity 2.4 times that of a cross roller bearing, 1.9 times that of a conventional standard two-row combination anguilla ball bearing, and 3.3 times that of a 4-point contact ball bearing.

[0090] The design preload clearance for each of the invention examples A to E, standard two-row combination anguilla ball bearing and 4-point contact ball bearing is 0.001 mm, and cross roller bearing is 0.001 mm. It is calculated as a typical value.

In addition, the appropriate ball diameter of the narrow ball bearing in the present embodiment varies depending on whether or not a seal or the like is mounted. However, in order to increase the rigidity tl, if the ball diameter is extremely small, the ball and inner / outer ring raceways are reduced. Since the contact pressure between the contact parts with the road groove increases and the pressure dent may be lowered, generally 30 to 90% of the bearing width (B) or (B2Z2) is desired! /.

In this embodiment, an annular seal body 120 is provided on one side of the single row ball bearing 100, and a cage 130 for positioning a large number of balls 103 in the circumferential direction is provided.

That is, as shown in FIG. 38, seal housing grooves 121 and 122 for housing the annular seal body 120 are disposed on one end face on the right side of the outer ring 101 and the inner ring 102, for example.

The annular seal body 120 is composed of a reinforced rubber seal 126 (for example, -tolyl rubber, acrylic rubber or fluororubber) reinforced with a metal core 125 formed in an inverted L shape. The rubber seal 126 has a fitting portion 126a that fits the outer ring 101 on the outer peripheral portion, and a lip portion 126b that contacts the inner ring 101 on the inner peripheral portion.

[0092] The seal housing groove 121 of the outer ring 101 has a relatively shallow step portion 121a on the right end side of the inclined inner peripheral surface 101b connected to the raceway groove 101a of the outer ring 101, and a circumferential shape at the bottom portion of the step portion 121a. A shallow portion into which the fitting portion 126a of the formed annular seal body 120 is pushed and inserted, and a fitting concave portion 121b, are provided.

Further, the seal receiving groove 122 of the inner ring 102 is relatively deeper than the right end of the groove 102a on the right side of the raceway groove 102a on the cylindrical outer peripheral surface 102b connected to the left and right ends of the raceway groove 102a of the inner ring. The annular seal body 12 formed in the circumferential direction on the bottom surface of the stepped portion 122a The lip portion 126b formed on the inner peripheral surface of 0 has a shallow receiving recess 122b that contacts the lip portion 126b.

Furthermore, the retainer 130 has a pair of annular portions 132a and 132b extending in the axial direction across the pocket portion 131 that accommodates the ball 103, and these annular portions 132a and 132b are the inner rings 10 2. The cylindrical outer peripheral surface 102b is mounted as a guide surface.

[0094] The cage 130 is made of a metal material such as a copper alloy manufactured by cutting, a synthetic resin material such as polyamide, polyacetal, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or glass. Manufactured with a synthetic resin material with reinforcing material added with reinforcing materials such as fiber and carbon fiber. When the cage 130 is formed of a resin material, either cutting molding or injection molding can be applied.

[0095] In addition, in the case of grease lubrication, the concave groove 133 provided in a part of the guide surface can play a role as a reservoir for holding a dull, and in addition, is located in the vicinity of the guide surface. In addition, there is an effect of appropriately supplying lubricating oil to the guide surface, and the wear resistance can be maintained for a long time from the viewpoint of the lubrication characteristics. This effect becomes more conspicuous when concave grooves 133 and 134 are formed in both annular portions 132a and 132b as shown in FIG.

Normally, when the annular seal body 120 is disposed on at least one side of the ball bearing 100, the force that uses the inner diameter surface of the outer ring 101 and the outer diameter surface of the inner ring 102 as the guide surface of the retainer 130. Since the intersection edge portion 123 is formed at the position where the groove 122 contacts, this intersection Due to the contact between the edge portion 123 and the annular portion 132b of the cage 130, the cage 130 is worn.

[0096] In order to prevent the wear of the cage 130, conventionally, when the inner ring guide is used, as shown in Fig. 47, the axial direction of the annular portion 132b on the intersection edge portion 123 side of the cage 130 is shown. It is considered that the length or width is shortened so that the annular portion 132b and the intersection edge portion 123 do not contact each other.

For this purpose, as shown in FIG. 48, it is necessary to increase the width of the annular portion 132b to ensure the strength. In this case, as described above, the inner portion of the annular portion 132b is increased. Since the circumferential surface and the intersection edge portion 123 face each other, when the cage 130 is inclined with respect to the guide-side raceway while the ball bearing 100 is rotating, the inner circumferential surface of the annular portion 132b is the intersection edge. The cage 130 will wear due to the edge hitting the part 123.

[0098] Further, the ball bearing 100 according to the present invention has a structure in which the ball diameter is very small with respect to the ball pitch circle diameter of the bearing, and accordingly, the cross-section of the annular portion 132b of the cage 130 is correspondingly reduced. And the radial strength of the cage 130 (radial strength of the annular portion 132b) is also reduced. In addition to this, the application of the ball bearing 100 according to the present invention tends to tilt the bearing because a large moment load is easily applied during rotation of the bearing due to its usage conditions. Therefore, due to the change in the contact angle of each ball 103, the revolution speed of each ball 103 varies, and the deformation of the cage 130 due to the tensile force between the ball 103 and the pocket 131 increases, which makes it easier to hit the edge. The contact surface pressure also increases and wear tends to progress.

[0099] However, as described above, in this embodiment, as shown in FIG. 38, the width of the annular portion 132b on the annular seal body 120 side of the cage 130 is increased to increase the cross-sectional area! However, since the concave groove 133 is formed at a portion where the seal receiving groove 122 and the cylindrical surface 102b serving as the guide surface may come into contact with the intersection edge portion 123, the cage 130 is inclined. Even so, a sufficient distance can be secured between the intersection edge portion 123 and the concave groove 133, so that the contact between the concave groove 133 and the intersection edge portion 123 can be reliably prevented and maintained. The wear of the vessel 130 can be reliably prevented. Further, in this embodiment, the normal line extension line L1 at the contact portion P1 that contacts the raceway groove 101a of the outer ring 101 of the ball 103 and the contact portion P2 that contacts the raceway groove 102a of the inner ring 102 interferes with the housing recess 122b. To avoid this, the contact angle is set to Θ force. For this reason, the distance Δ between the parallel line L2 parallel to the extension line L1 and in contact with the receiving recess 122b is set to Δ> 0. Here, the contact angle Θ is the height of the groove of the inner ring and outer ring, the ratio of the ball diameter to the bearing width, and the force that varies depending on the shape and size of the seal receiving recess 122b. More desirably, 40 ° or less is preferable, but if it is less than 20 °, the allowable axial load and allowable moment load are reduced, which is preferable.

[0100] In this way, by setting the contact angle Θ, the extension line L1 in the normal direction of the contact portions P1 and P2, which is the direction in which the rolling element load is applied, becomes the accommodation recess 122b that accommodates the annular seal body 120 On the other hand, it passes through a position separated by a distance Δ (> 0), and it is reliably prevented that the rolling element load is borne only by the shoulder of the inner ring groove, and the inner ring presser 140 shown by the chain line in FIG. The rolling element load can be received by the inner ring 102 and the shaft (not shown) fitted to the inner ring 102 to be raised, and the groove shoulder 102c is deformed to receive the rolling element load without causing a decrease in rigidity. Can Therefore, even when a narrow anguilla ball bearing is subjected to a large moment load, it is possible to extend the life of the bearing without causing breakage or chipping at the groove shoulder 102c. In the above embodiment, the force described in the case where the annular seal body 120 is disposed on the right side of the ball bearing 100 is not limited thereto. The annular seal body 120 is disposed on the left side of the ball bearing 100. However, it is also possible to arrange an annular seal body 120 on both sides.

[0101] Further, in the above-described modification, the case where the concave groove 133 formed in the annular portion 132b is formed in a semicircular cross section is described. However, the present invention is not limited to this. Any shape can be used as long as it can avoid contact with the intersection edge portion 123 such as an elliptical cross section.

Further, in the above modification, the annular seal body 120 contacts the inner ring seal housing groove 122. The force described in this case is not limited to this. The inner ring seal shown in Fig. 50 does not come into contact with the receiving groove 122 ヽ Apply a non-contact rubber seal type (with a metal core) or a metal seal that is tightened in the outer ring seal groove. Can do.

[0102] Furthermore, in the above-described embodiment, the case where the guide surface of the retainer 130 is the outer peripheral surface of the inner ring 102 has been described, but the inner peripheral surface of the outer ring 101 is not limited to this and is used as the guide surface. You may do it.

Furthermore, in the above embodiment, the force described in the case where the concave groove 133 is formed in the annular portion 132b on the annular seal body 120 side among the annular portions 132a and 132b of the cage 130 is not limited to this. As shown in FIG. 49, the annular seal part 120a opposite to the annular seal body 120 is symmetrical with respect to the concave groove 133 of the annular part 132b and the vertical plane passing through the center of each ball 103. A concave groove 134 may be provided at the position. In this way, when the concave groove is formed in the left and right annular portions 132a and 132b, it can be assembled from any direction without confirming the position of the concave groove of the retainer 130 during assembly, improving the assembly work. Can be made.

[0103] Further, in addition to the present embodiment, as shown in Fig. 51, the cage has an annular seal body 104 attached to one end in the axial direction (the end opposite to the end face on the combination side), In addition, when an anguilla ball bearing 100 equipped with a cage 110 that holds the ball 103 in a rollable manner is combined in the back of two rows, as shown in FIGS. 52 and 53, an annular portion 111 and the annular portion 111 A plurality of pillars 112 projecting in a plurality of axial directions at substantially equal intervals in the circumferential direction at one end of each of them, and a pocket part 113 formed between the pillars 112 to hold the balls 103 so as to be rollable in the circumferential direction. Even with a flexible inner ring outer diameter surface and a cantilevered ring structure cage that does not use the outer ring inner diameter surface as a guide surface, that is, a ball guide crown-shaped cage 110 that does not contact the inner ring-outer ring. Good. When two single-row ball bearings are combined in this way, as shown in Fig. 51, if the axial pitch of the balls 103 is shifted as much as possible to the opposite side of the end face on the combination side (X> X), the cage Thickness in the axial direction of the ring

1 2

The distance between the operating points can be increased to increase the moment rigidity. Further, a full ball anguilla ball bearing without a cage may be applied.

[0104] In the above embodiment, the pitch circle diameter of the balls 103 is as shown in the following equation (4). However, if it is desired to further increase the moment stiffness by increasing the number of balls per row, (Five ), The pitch circle diameter of the ball 103 may be shifted to the outer ring side, and if necessary, the pitch circle diameter of the ball 103 is moved to the inner ring 102 side by using the following equation (6). Even if you shift it (not shown).

Ball pitch circle diameter = (inner ring inner diameter + outer ring outer diameter) Z2--(4)

Ball pitch circle diameter> (inner ring inner diameter + outer ring outer diameter) Z2--(5)

Ball pitch circle diameter (inner ring inner diameter + outer ring outer diameter) Z2--(6)

Further, if necessary, the ball pitch circle diameters of the left and right ball bearings to be combined need not be the same value, and the diameters of the balls 103 of the left and right ball bearings to be combined need not be the same value. In addition, the cross-sectional dimension ratio (BZH) of the two ball bearings to be combined is not the same. For example, the smaller ball diameter is (BZH) = 0.28 and the larger ball diameter is (BZH) = 0.62. I do not care. In addition, the axial pitch of the balls 103 is shifted in the axial direction in order to secure the distance between the application points of the seals and cages and the moment action point, even if the axial pitch of the balls 103 is not centered in the axial direction. Also good.

[0105] Next, with reference to FIG. 54, a double-row anguilla ball bearing which is an example of the second embodiment of the third embodiment will be described.

This double-row anguilla ball bearing 200 has a large number of balls 203 rotatably arranged between the double-row raceway grooves 201a and 201b of the outer ring 201 and the double-row raceway grooves 202a and 202b of the inner ring 202. The cross-sectional dimension ratio (B2ZH2) between the width B2 and the radial section height H2 (= (outer ring outer diameter D2—inner ring inner diameter d2) / 2) is (B2ZH2X1.2), and the ball pitch circle diameter is radial. It is set at the center of the section height.

Then, seal housing grooves 121 and 122 similar to those of the first embodiment in the third embodiment are formed on the left and right side surfaces of the outer ring 201 and the inner ring 202, respectively, and annular seal bodies are formed in these seal housing grooves 121 and 122, respectively. 120 are housed in the left and right objects.

Here, in this embodiment, a case where the double row ball bearing 200 is replaced with a 7208A (contact angle 35 °) two-row combined angular ball bearing is taken as an example.

The 7208A has an inner ring inner diameter of 40 mm, an outer ring outer diameter of 80 mm, and an axial sectional width (bearing unit width): B is 18 mm, so the sectional dimension ratio (BZH) is 0.9. Therefore, in the angular contact ball bearing 200 of this embodiment, the cross-sectional dimension ratio (B2ZH2) = 0.90 (inner ring inner diameter and outer The outer diameter of the ring remains the same, but the axial cross-sectional width (bearing unit width): B2 is 18 mm). As a result, it is possible to receive radial load, axial load in both directions, and moment load, as well as to save 1Z2 space in the axial dimension, lower torque, and higher rigidity.

Of course, if necessary, the cross-sectional dimension ratio (B2ZH2) may be set to be less than 0.90 or more than 0.90 (however, (B2ZH2X1.2).

Then, the contact angle of the anguilla ball bearing 200 is set to 35 °, for example, similarly to the first embodiment in the third embodiment described above, and the raceway grooves 201a, 201b of the outer ring 201 and the inner ring 202 of the ball 203 and The extension lines LI in the normal direction of the contact portions PI and P2 with 202a and 202b are set so as to pass through a position separated by a predetermined distance Δ (> 0) from the receiving recess 122b.

[0108] In the second embodiment of the third embodiment as well, the extension line L1 in the normal direction of the contact portion P1 and the flange 2 does not interfere with the housing recess 122b of the seal housing groove 122. Since the contact angle Θ is set for the inner ring 20 2 and the inner ring backed up by the inner ring presser, it is not necessary to bear this rolling element load only at the groove shoulder when a large rolling element load is applied. It can be received by a shaft to be inserted (not shown), and can prevent deformation of the groove shoulder and prevent breakage or chipping of the groove shoulder, thereby improving the life of the narrow double row anguilla bearing. Can be prolonged.

In the second embodiment of the third embodiment as well, in order to increase the moment rigidity, the ball pitch circle diameter is shifted to the outer diameter side with the double-row anguilla ball bearing 200, or the double-row anguilla ball In the bearing 200, the ball diameter of each row may be changed.

Also, double row full ball anguilla ball bearings are also available without cage.

In any of the examples, in addition to the structure of the annular seal body, the cage, etc. and whether or not it is mounted, the application example related to the structure is the single row ball bearing described in the first embodiment of the third embodiment. According to Further, as in the first embodiment in the third embodiment, it may be used under any conditions of preload and clearance.

[0110] Further, in the first embodiment of the third embodiment, the fitting recess 121b and the housing recess for housing the annular seal body 120 connected to the shoulder portion 102c only on the inner ring 102 side. The force described in the case of forming 122b is not limited to this. In FIG. 38, an annular seal is connected to the groove shoulders of the outer ring 101 and the inner ring 102 as a shape reversed left and right by a vertical line passing through the center of the ball 103. The present invention can also be applied to the case where an accommodation recess for accommodating the body 120 is formed. Here, the annular seal body 120 may be provided on both the left and right sides.

[0111] Further, in the first and second embodiments of the third embodiment, the fitting recess 121b for housing the annular seal body 120 and the housing recess 122b extend over the entire circumference in the circumferential direction. The force described for the case where it is formed The present invention can be applied to the case where the concave step portion is formed in a part of the circumferential direction. Furthermore, the concave step portion is not limited to the one for accommodating the annular seal body 120, and a concave step portion used for any application can be applied.

[0112] Next, a spindle turning part and a rotary table of a machine tool, an industrial machine, a joint part and a turning mechanism part of a robot, a medical device, and a semiconductor Z liquid crystal manufacturing apparatus, which are examples of the fourth embodiment of the present invention. The ball bearings used in applications in which radial loads and axial loads in both directions, particularly large moment loads, act as loads, will be described with regard to combination ball bearings used in optical and optoelectronic devices.

Normally, in ball bearings such as deep groove ball bearings, as shown in Fig. 55, the balls 83 are rotatably held between the raceways of the inner ring 82 and the outer ring 81 to hold the sealed grease and prevent leakage to the outside. Alternatively, a seal 85 is attached to the end surface in the axial direction between the inner ring 82 and the outer ring 81 for the purpose of preventing foreign matter from entering the bearing from the outside. As shown in Fig. 56, the ball guide retainer 84 for holding the ball 83 has a crown-shaped (cantilever ring structure) ball guide synthetic resin holding the required number of pockets 86b on the ring 86a. Standard equipment is used.

[0113] As shown in Fig. 56, the ball guide retainer 84 has a pocket inner surface 86c that normally holds the ball 83, and is formed in a spherical shape having a curvature slightly larger than the curvature of the ball 83. As shown in Fig. 57, the movement amount of the cage 84 in the radial direction is the smaller of the clearance AR between the ball 83 and the pocket inner diameter end surface or the clearance AR between the ball 83 and the pocket outer diameter side end surface. In position

1 2

It is decided. In addition, as shown in FIG. 58, the axial movement amount of the cage 84 is determined by the clearance AS between the ring-side pocket inner surface 86c and the ball 83 in one direction, and in the other direction by the pocket column portion 86d.

1

It is positioned by the clearance ΔS between the ball locking portion 86e formed at the tip and the ball 83.

2

[0114] The cage 84 is usually manufactured by injection molding. When the cage is separated from the mold, the cage 84 is separated in the axial direction (so-called axial draw type). At this time, the relationship between the inner diameter φ d of the pocket surface and the distance between the pair of ball engaging portions 86e, that is, the diameter H of the mouth is φ d

P P

Therefore, when the mold is released, the ball engaging portion 86e is deformed when a molding die member (spherical member) for forming a pocket passes therethrough. You have to take the so-called unreasonable form. Therefore, it is necessary for the ball engaging portion 86e to retain flexibility so as not to leave breakage, cracks, or a large plastic deformation that may cause a functional problem when released.

[0115] In addition, the ball engaging portion 86e has a relationship of the ball diameter φ D force S φ D> H with respect to the outer diameter H of the mouth between the opposing ball engaging portions 86e. When the cage 84 is assembled to the bearing, Ie ball 83 pocket aa

When inserting into the part 86b, it is necessary that the ball engaging part 86e is not damaged or missing when passing between the ball engaging parts 86e. The structure is such that it cannot be removed from the ball 83.

Under normal general rotation conditions, the cage 84 is unlikely to come out of the ball 83, but the vibration during rotation of the bearing is large, or the inclination between the outer ring 81 and the inner ring 82 due to moment load or other factors. Therefore, in applications where an eccentric load is applied to the ball locking portion 86e of the cage 84, it is easy to come off, so it is necessary to maintain a strength that prevents the cage 84 from falling off in the axial direction.

[0116] If at least some of the pockets 86b dislodge the balls 83 in the axial direction, adjacent balls in the circumferential direction come into contact with each other, and heat generation or wear occurs due to sliding contact between the balls. In some cases, seizure will result in damage to the balls. The cage 84 also suffers from defects such as wear and chipping due to the uneven contact of the drop-off point.

In order to satisfy the conflicting requirements of the above-mentioned applications, select the appropriate cage resin material, select the content of reinforcing materials such as glass fiber, and select the optimal ball locking part 86e. Several problems must be solved before the final specification design is established, such as the selection of the diameter H. [0117] On the other hand, in the case of an anguilla ball bearing, as shown in FIGS. 59 and 60, a so-called rice bran cage 87 having a double-sided ring structure is generally used. — 3 In the case of a narrow ball bearing as shown in Japanese Patent No. 33588 (hereinafter referred to as Patent Document 4), a crown-shaped cantilever ring structure is used as a measure to further reduce the axial width of the ball bearing. A ball guide cage has been proposed.

However, in the narrow anguilla ball bearing disclosed in Patent Document 4, the ball diameter must be particularly small because the axial width of the bearing is narrowed for the purpose of space saving in the axial direction. In addition, since the annular strength of the ring portion is reduced because the cross-sectional thickness of the cage is thin and the cage is easily deformed, the cage is likely to be pulled out in the axial direction as described above. There is.

[0118] In particular, in the above-described applications, a large moment load often acts as a load, and the ball revolving speed varies due to variations in the load load of each ball. There is concern that the cage may be deformed due to an unbalanced load and the cage may be pulled out in the axial direction due to the load applied to the ball locking portion. When the cage strength is extremely increased, as described above, the locking portion may be damaged or cracked due to the deformation load when the ball passes through the locking portion when released from the mold or when the cage is incorporated. Occurrence and plastic deformation will occur.

[0119] Therefore, the fourth embodiment of the present invention has been made by paying attention to the unsolved problems of the above-described conventional example, and when a crown-shaped cage is used for the purpose of space saving in the axial direction. An object of the present invention is to provide a ball bearing that does not cause the cage to be disengaged in the axial direction and that can exhibit stable rotational performance without causing wear or damage to the ball or damage to the cage. Yes.

To achieve the above object, the combination ball bearing according to the first embodiment of the fourth embodiment of the present invention is configured by combining two rows of narrow ball bearings, and each narrow ball bearing is arranged on one side. A combined ball bearing having a ring portion and a crown-shaped ball guide retainer having a required number of pocket portions for holding balls on the other side of the ring portion, the ring portion side being arranged on the combination surface side. The pocket portion has a ball locking portion that prevents a ball formed at a tip portion opposite to the ring portion from being pulled out, and the center of curvature of the pocket portion and the ball locking portion. The center of curvature of the pocket and the center of curvature of the pocket are matched to the axial distance from the tip. The axial clearance between the ring portion end portions of two opposing cages in the state is set so that the value obtained by adjusting the axial clearance between the pocket surface of the pocket portion and the ball is small. Yes.

[0120] Further, the combination ball bearing according to the second embodiment in the fourth embodiment of the present invention is the invention according to the first embodiment, wherein the ball guide retainer is formed of a synthetic resin material. It is characterized by that.

Furthermore, the combination ball bearing according to the third embodiment of the fourth embodiment of the present invention is the invention according to the first or second embodiment, wherein each of the narrow ball bearings is the ball guide cage. An annular seal body is provided on the inner ring and the outer ring axial end surface on the opposite side of the ring part side and the ball. /

[0121] Furthermore, the combined ball bearing according to the fourth embodiment of the fourth embodiment of the present invention is the invention according to the third embodiment, wherein the annular seal body is the narrow ball bearing. It is characterized by being in contact with at least one of the outer ring and the inner ring.

Furthermore, the double row ball bearing according to the fifth embodiment of the fourth embodiment of the present invention has a narrow double row ball bearing configuration, and each row has a ring portion on one side. The crown-shaped ball guide retainer having the required number of pocket portions for holding balls on the other side of the ring portion is arranged in a double row with the ring portion facing the inner side in the axial direction of the bearing. In the ball bearing, the pocket portion has a ball locking portion that prevents a ball formed at a tip portion on the opposite side of the ring portion, and a center of curvature of the pocket portion and the ball locking portion. In the axial clearance between the two ring holder ends facing each other in a state where the center of curvature of the pocket and the center of curvature of the ball coincide with the axial distance from the tip, the pocket The value force S with the axial clearance between the pocket surface and the ball is set to be small. It is characterized by that.

[0122] Further, in the double row ball bearing according to the sixth embodiment of the fourth embodiment of the present invention, in the fifth embodiment, the ball guide cage is formed of a synthetic resin material. It is characterized by that.

Furthermore, the double row ball bearing according to the seventh embodiment of the fourth embodiment of the present invention is the above-mentioned fifth or sixth embodiment, wherein the double row ball bearing is a ring of the ball guide retainer. An annular seal body is disposed on the inner side and outer ring axial end surface portions on the opposite side through the ball side and the ball side.

[0123] Furthermore, the double row ball bearing according to the eighth embodiment of the fourth embodiment of the present invention is the above seventh embodiment, wherein the annular seal body includes the outer ring of the narrow ball bearing and It is characterized by being in contact with at least one of the inner rings.

According to the fourth embodiment of the present invention, in a combined bearing in which two rows of narrow ball bearings are combined or a double row ball bearing having a narrow width, the center of curvature of the pocket portion, the tip of the ball locking portion, The pocket surface of the pocket portion has a gap in the axial direction between the end portions of the ring portions of the two opposing cages in a state in which the center of curvature of the pocket portion and the center of curvature of the ball coincide with each other. Since the axial clearance between the ball and the ball is set to be small, when the cage moves in the axial direction due to inner / outer ring inclination due to moment load, etc., the other combined bearing is held. By contacting the bowl end surface, the ball does not slip until the large diameter part of the ball exceeds the ball locking part, so it is possible to reliably prevent the ball and the cage from falling off! /, Effect.

Hereinafter, an embodiment of the fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 61 is a cross-sectional view of the principal part showing a state in which two single-row ball bearings according to the first embodiment of the fourth embodiment of the present invention are combined, and FIG. 62 is a cross-sectional dimension ratio (BZH) and radial inner dimensions. Fig. 63 is a graph showing the relationship between the deformation of the outer ring, Fig. 63 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the secondary moment I of the cross section, and Fig. 64 is for explaining the deformation in the radial direction of the inner ring. Fig. 65 is an explanatory diagram for explaining the method of calculating the secondary moment of inertia of the inner ring. Fig. 66 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the deformation amount of the inner and outer rings in the radial direction. Fig. 67 is a graph showing the relationship between the cross-sectional dimension ratio (BZH) and the cross-sectional secondary moment I, Fig. 68 is a graph showing a comparison of the calculated moment stiffness of various bearings, and Fig. 69 is a cross-section showing a ball guide cage. Fig. 70 is a partial perspective view of the cage as seen from the radial inner force.Fig. 71 is an arrow view as seen from the arrow Y direction of Fig. 69. 72 Z- Z line sectional view of FIG. 69, FIG. 73 is an explanatory diagram for explaining the operation when the retainer is moved in the axial direction, FIG. 74 is a palm view also seen the arrow X direction forces in Figure 69.

[0125] The combination bearing 100 of the present invention includes two single-row anguilla ball bearings 300 as shown in FIG. It has a configuration in which A and 300B are combined in two rows so that the contact angle represents a square shape.

Here, in each of the single-row angular bearings 300A and 300B, as shown in FIG. 61, a large number of balls 303 are arranged between the raceway groove 301a of the outer ring 301 and the raceway groove 302a of the inner ring 302 so as to be able to roll. It has a configuration of a narrow bearing provided.

In addition, the material of the inner ring 302, outer ring 301 and ball 303 is a bearing steel (eg, SUJ2, SUJ3, etc.) under standard operating conditions. Depending on the usage environment, the stainless steel material (eg, SUS440C) is a corrosion resistant material. Martensitic stainless steel such as SUS304, austenitic stainless steel such as SUS304, precipitation hardened stainless steel such as SUS630), titanium alloy and ceramic materials (eg Si N, SiC, Al O, ZrO etc.) The

3 4 2 3 2

A little.

[0126] The lubrication method is not particularly limited, and in general use environment, mineral oil-based grease or synthetic oil-based

Grease and oil (for example, lithium-based and urea-based) can be used. For high temperature environment applications, fluorine grease or fluorine oil, fluorine resin, MoS

Solid lubricants such as 2 can be used.

Narrow bearings are bearings of a size that do not fit the standard angular bearings (78 XX, 79 XX, 70 XX, 72 XX, 73 XX series, etc.) specified by the International Organization for Standardization (ISO). Bearing with axial sectional width B and radial sectional height H (= (outer ring outer diameter D—inner ring inner diameter d) / 2) sectional dimension ratio (BZH) (BZH) <0.63 It is.

[0127] In addition, a narrow double-row ball bearing has an axial cross-sectional width B2 and a radial cross-sectional height H2 (= (outer ring outer diameter D2—inner ring inner diameter d2) Z2 cross-sectional dimension ratio (B2ZH2) ( B2ZH2) <1. 2. This is a narrow double row anguilla high ball bearing.

For example, in the case of 7208A (angular ball bearing with a contact angle of 30 degrees) as a conventional ball bearing, the inner ring inner diameter is φ40mm, the outer ring outer diameter is φ80mm, and the axial sectional width (bearing unit width) B is 18mm. The dimension ratio (BZH) is 0.9.

Therefore, in the angular contact ball bearings 300A and 300B of the present embodiment, the cross-sectional dimension ratio (B / H) = 0.45 (the inner ring inner diameter and the outer ring outer diameter remain the same, and the axial sectional width (bearing single body width) is 9mm). As a result, radial load, axial load in both directions, and moment load can be received, and space saving of 1Z2 in the axial dimension can be achieved. It can be replaced with a single row 7208A, and lower torque and higher rigidity can be achieved.

[0129] Of course, if necessary, the cross-sectional dimension ratio (BZH) of the anguilla ball bearing 300 may be set to less than 0.45 or more than 0.45 (however, (BZH) is less than 0.63). It does n’t turn.

Thus, the reason for B / H <0.63 is as follows.

Figures 62 and 63 show the standard thin ball bearings (inner diameter: φ 3 8. lmm, outer diameter of bearing: 47.625mm, bearing width: 4.762mm, cross-sectional dimension ratio (BZ H ) = Based on 1), the radial deformation characteristics of the inner and outer ring rings when the bearing inner diameter is changed without changing the bearing outer diameter and bearing width (ie, when the value of (BZH) is changed) (See Fig. 64: Example of inner ring) and the radial cross-sectional secondary moment I (see Fig. 65: I = bh ³ Z 12) is shown for comparison.

[0130] Also, as shown in Figs. 66 and 67, the ultra-thin ball bearings used as standard (Bearing inner diameter: Φ 63.5 mm, Bearing outer diameter: φ 76.2 mm, Bearing width: 6. 35 mm, Inner and outer rings when the inner diameter of the bearing is changed (that is, the value of (BZH) is changed) without changing the outer diameter and width of the bearing, based on the cross-sectional dimension ratio (BZH) = 1). The results of comparing the radial deformation characteristics of the ring and the radial moment of inertia I are shown.

[0131] Therefore, in this embodiment, it is possible to prevent bearing deformation due to the processing force during lathe machining and grinding during the production of inner and outer rings, which is a problem with conventional ultrathin bearings. The bearing accuracy can be improved.

[0132] In single-row ball bearings, it is difficult to apply preload or moment load in one row, but by combining two or more rows, radial load, axial load and And moment load can be applied.

[0133] Furthermore, the width is about half that of the conventional standard single row ball bearing, so the ball diameter is also about half that of the conventional ball bearing, but conversely, the number of balls per row increases, Bearing rigidity is increased compared to conventional ball bearings. Also, when applied to the arm joint of a turning robot, etc., since the rotation speed is mostly low, rolling fatigue life time is practical even if the load capacity of the bearing is reduced by reducing the ball diameter. There is no problem.

Other industrial machines, robot joints and swiveling mechanisms, rotating tables and spindle turning mechanisms for machine tools, medical equipment, semiconductor Z liquid crystal manufacturing equipment, optics and optoelectronics equipment, etc. have low rotation speeds. Since there are many applications and rocking and rotating applications, rolling fatigue life time is rarely a problem.

[0134] Fig. 68 is a comparison of calculated moment stiffness of various bearings. For the same size (calculation example is equivalent to bearing name 7906A (contact angle 30 °) and the inner and outer diameter dimensions are the same: inner ring inner diameter φ 30 mm, outer ring outer diameter φ 47 mm), the first in the fourth embodiment Example A of the present invention in which the two-row combination narrow angular contact ball bearing (contact angle 30 °: calculation example of bearing) according to the embodiment and the raceway groove radius of curvature (Da is the ball diameter) of the inner and outer rings are changed. E has a higher moment stiffness than cross roller bearings, standard two-row combination anguillar ball bearings and 4-point contact ball bearings.For example, Example B of the present invention is 2.4 times the cross roller bearing, It is possible to maintain a moment stiffness 1.9 times that of conventional standard two-row combination anguillar ball bearings and 3.3 times that of 4-point contact ball bearings.

[0135] The design preload clearance for each of the invention examples A to E, standard two-row combined angular contact ball bearings and 4-point contact ball bearings is 0. OlOmm, and the cross roller bearing is 0.001mm. It is calculated as a typical value.

In addition, the appropriate ball diameter of the narrow ball bearing in the present embodiment varies depending on whether or not a seal or the like is mounted. However, in order to increase the rigidity tl, if the ball diameter is extremely small, the ball and inner / outer ring raceways are reduced. Since the surface pressure between the contact parts with the road groove increases and the pressure dent resistance may decrease, 30 to 90% of the width (B) is desirable.

[0136] Note that the contact angle Θ is approximately 60 ° or less, preferably 50 ° or less in order to prevent the ball and the inner / outer ring groove contact portion from climbing onto the shoulder portion of the inner / outer ring groove when a large moment load is applied. 40 ° or less is more desirable, but if it is less than 20 °, the allowable axial load or allowable moment load will be reduced.

In this embodiment, a ball guide retainer 310 for positioning a large number of balls 303 in the circumferential direction is disposed on the combined surface side of the single-row angular bearings 300A and 300B, and an annular seal is provided on the opposite side to the combined surface. The body 320 is disposed.

As shown in FIGS. 69 to 71, for example, the ball guide retainer 310 protrudes in the axial direction at a plurality of locations at substantially equal intervals in the circumferential direction on the ring portion 311 and one end portion of the ring portion 311. Pillar portions 312 formed between the pillar portions 312 and a plurality of pocket portions 313 formed between the pillar portions 312 so as to be able to roll the balls 303 in the circumferential direction, and tip portions of the pocket portions 313 opposite to the ring portions 311 And a pair of ball locking portions 314 for preventing the balls 303 formed from being pulled out from each other. The material of the cage 310 is, for example, a synthetic resin material such as polyamide, polyacetal, or polyphenylene sulfide, and a material in which a reinforcing material such as glass fiber or carbon fiber is mixed in the synthetic resin material is used as necessary. .

Then, as shown in FIG. 61, ball guide retainer 310 is arranged in single row anguilla ball bearings 300A and 300B so that ring portion 311 is on the combination surface side.

Here, as shown in FIG. 72, the center of curvature O of the pocket portion 313 and the center of curvature of the ball 303 coincide with the axial distance L between the center of curvature O of the pocket portion 313 and the tip of the ball locking portion 314. The value obtained by adding the axial clearance ΔP between the pocket surface 313a of the pocket portion 313 and the ball 303 to the axial clearance ΔG between the ends of the ring portion 311 in the two opposing cages 310 in the state ΔG + Δ P is set to be small as shown in the following formula (7)!

[0139] L> A G + Δ Ρ (7)

With such a dimensional configuration, due to the inner and outer ring inclinations due to moment load, etc., as shown in FIG. 73, one single row angular contact ball bearing, for example, 300A, the cage 310 is shown in the solid line from the state shown in the chain line. When the ring portion 311 is moved in the axial direction, the ring portion 311 comes into contact with the ring portion 311 of the cage 310 of the other single-row anguilla ball bearing 300B. The large diameter portion of 303 does not exceed the tip of the ball locking portion 314 (that is, Δ in FIG. 73 becomes a positive value), and the cage 310 is dropped, that is, the ball 303 is released from the pocket portion 313. This can be reliably prevented (that is, a margin of Δ in FIG. 73 remains).

[0140] Here, the cages 310 of the anguilla ball bearings 300A and 300B both revolve at substantially the same speed, and the relative sliding speed of the cages 310 is extremely small, and both are in contact with a flat surface. Therefore, it is difficult for the contact portion to be worn or damaged.

The above configuration cannot be effective when a single-row bearing is used. However, an angular ball bearing can only apply an axial load in one direction in the single-row structure. In most cases, it is used in a combination of more than one row, and the frequency of application when implemented is high.

[0141] By disposing the cage 310 so as to have the relationship of the above formula (7) in the combined bearing 300, the cage 310 can be reliably prevented from coming off from the ball 303, and the cage 3 The range of selection of the shape design of the 10 ball locking portions 314 can be expanded, and the design becomes easy. In this embodiment, in order to increase the load capacity and rigidity of the bearing, the circumferential pitch between the adjacent balls 303 is shifted as much as possible to the opposite side of the end face on the combination side (FIG. 61: X> X).

1 2 The ring part 311 of the cage 310 is arranged so as to be on the bearing combination end face side, so that the distance between the action points for increasing moment rigidity can be increased.

[0142] FIG. 74 (b) is a crown-shaped cage having the same basic structure as FIG. 74 (a), but the ring portion 311 has a gap between the pocket portions 313 adjacent to each other at least at one place in the circumferential direction. It has a structure in which a predetermined gap is provided between the cut surfaces by cutting in advance.

By adopting such a structure, the rolling element pitch circle diameter and the cage pitch circle diameter are shifted due to the difference in thermal expansion coefficient between the cage and the inner and outer rings and the variation in dimensional accuracy and roundness of the cage. Even in this case, both the radial flexibility due to the cantilever shape and the elastic deformation in the circumferential direction (circumferential flexibility) due to the gaps between the cut surfaces are combined. This prevents the cage from being damaged or worn by buffering the tension between the ball and the pocket 313, and also reduces torque unevenness and heat generation due to sliding contact resistance between the ball 303 and the pocket 313. .

[0143] In addition, the ball bearing of the present invention is structurally small in the diameter of the ball used. The radial thickness of 11 cannot be increased (as can be understood from FIG. 61, the cage needs to be positioned with an appropriate gap in the gap between the outer diameter of the inner ring and the inner diameter of the outer ring. The gap between the outer diameter and the inner diameter of the outer ring is narrow because it is approximately proportional to the ball diameter. In addition, due to the narrow structure, the axial gap and the axial thickness must be reduced. . As a result, the cage ring part is extremely smaller than the standard size bearing, so that dimensional accuracy such as roundness can be obtained, so the cage structure with the ring part 311 as shown in Fig. 74 (b) is particularly The above-described cage damage and wear prevention effects, and torque unevenness and heat generation reduction effects can be obtained.

Next, as shown in FIG. 75, the annular seal body 320 is configured to be in contact or non-contact with the inner ring 302 or the outer ring 301 corresponding to the side where the annular seal body 320 is inserted. ing. The annular seal body 320 is disposed on the opposite end surfaces of the inner and outer ring axial directions through the ring portion 311 and the ball 303 of the cage 310 of both single-row angular bearings 300A and 300B.

The annular seal body 320 is accommodated in seal housing grooves 321 and 322 formed in the axial end surfaces of the outer ring 301 and the inner ring 302.

[0145] The annular seal body 320 is a non-contact type (non-contact with the inner ring 302) inserted into the fitting groove 321a formed in the seal housing groove 321 of the outer ring 301, and an inverted L-shaped metal core 325 Reinforced rubber seal (for example, -tolyl rubber, acrylic rubber or fluoro rubber) 326 reinforced with

Here, the rubber seal 326 of the single row angular contact ball bearing 300A includes a fitting portion 326a fitted into the fitting groove 321a, and an annular shape extending from the fitting portion 326a toward the inner ring 302 while being curved outward in the axial direction. And a plate portion 326b. Further, the rubber seal 326 of the single row anguilla ball bearing 300B has a plane symmetrical shape with the rubber seal 326 of the single row anguilla ball bearing 300A sandwiching the combination surface.

[0146] By forming the rubber seal 326 of the annular seal body 320 in this way, the internal space volume between the annular seal body 320 and the ball 303 can be maintained, which corresponds to the vicinity of the ball 303 as shown in FIG. It is possible to enclose an amount of grease. In addition, since the distance between the ball 303 and the seal surface is close, the grease adhering to the seal is also circulated by rotation, which can contribute to lubrication of the rolling contact portion. Further, on the combined surface side of the single-row angular bearings 300A and 300B, the ring portion 311 of the cage 310 causes the outer diameter surface of the outer ring 301 and the outer diameter surface of the ring portion 311 and the outer diameter surface and the ring portion of the inner ring 302 by the ring portion 311. The opening between the inner diameter surfaces of 311 is narrow and doubles as a labyrinth mechanism. For this reason, the grease can be prevented from leaking to the combined surface, and the bearing can be easily handled until the bearing is assembled in the machine. In the configuration of the above embodiment, the seal mounting side is the outer end surface after the bearing is assembled. Since the ring 311 side of the cage 310 is an opposing surface of the two bearings, foreign matter and dust can be reliably prevented from entering the bearing if grease leaks.

[0147] In the above embodiment, the force S described in the case where the two single-row anguilla ball bearings 300A and 300B are combined on the back surface with a contact angle of a square shape is shown in Fig. 76, which is not limited to this. As shown, make sure that the contact angle is in the shape of an inverted letter C.

Further, in the above embodiment, the force described for the case where the annular seal body 320 is a non-contact type that does not contact the inner ring seal housing groove 322 is not limited to this. The inner ring seal housing groove 322 shown in FIG. A contact-type annular seal body having a lip portion 327 to be contacted or a metal seal that is caulked in an outer ring seal groove can be applied. In contrast to the above-described embodiment, an annular seal body 320 may be fitted on the inner ring 302 side so as to be in contact or non-contact with the outer ring.

[0148] In the above embodiment, the pitch circle diameter of the balls 303 is as shown in the following formula (8). When the number of balls per row of force bearings is increased to further increase the moment rigidity, the following formula ( 9) may be adopted to shift the pitch circle diameter of the ball 303 to the outer ring side, or the following equation (10) may be adopted if necessary to reverse the pitch circle diameter of the ball 303 to the inner ring 302 side. It may be shifted to (not shown).

Ball pitch circle diameter = (inner ring inner diameter + outer ring outer diameter) Z2--(8)

Ball pitch circle diameter> (inner ring inner diameter + outer ring outer diameter) Z2--(9)

Ball pitch circle diameter <(inner ring inner diameter + outer ring outer diameter) Z2 ~ (10)

If necessary, the ball pitch circle diameters of the left and right ball bearings to be combined need not be the same value, and the diameters of the balls 303 of the left and right ball bearings to be combined need not be the same value. In addition, the cross-sectional dimension ratio (BZH) of the two ball bearings to be combined is not the same. For example, the smaller ball diameter is (BZH) = 0.28 and the larger ball diameter is (BZH) = 0.62. I do not care. In addition, the axial pitch of the balls 103 is shifted in the axial direction in order to ensure that the axial pitch of the balls 303 is not centered in the axial direction and to secure the distance between the action points of the seals and cages and the moment. Also good.

[0149] In addition, in the above-described embodiment, a preloaded clearance combined angular ball bearing is used in order to increase the moment rigidity. However, when rigidity and accuracy are not so required (reversely, a lower torque requires a lower temperature rise). If necessary, a combination of clearance anguilla ball bearings may be used.

Next, with reference to FIG. 78, a double row anguilla ball bearing which is an example of the fifth embodiment of the fourth embodiment of the present invention will be described.

[0150] In this double row anguilla ball bearing 400, a number of balls 403 are held between the double row raceway groove 401a of the outer ring 401 and the raceway grooves 402a of the two inner rings 402A and 402B formed separately from each other. The section dimension ratio (B2ZH2) between the axial section width B2 and the radial section height H2 (= (outer ring outer diameter D2—inner ring inner diameter d2) / 2) is (B2ZH2) < 1.2.

Here, the cage 410 is a crown-shaped cage having the same configuration as that of the first embodiment described above, and the same reference numerals are given to the corresponding parts to the first embodiment, and the detailed description thereof will be given here. Although omitted, as shown in FIG. 72 in the first embodiment described above, the pocket portion 313 curvature with respect to the axial distance L between the curvature center O of the pocket portion 313 and the tip of the ball locking portion 314. The axial clearance between the ends of the ring portions 311 of the two opposing cages 310 in a state where the center O and the center of curvature of the balls 403 coincide with each other in the axial clearance AG between the pocket surfaces 313a of the pocket portions 313 and the balls 403. The value obtained by adjusting the axial clearance Δ P Δ G + Δ P is set to be small !, (L> A G + Δ Ρ) ₀

[0151] Then, seal receiving grooves 421 and 422 similar to those in the first embodiment are formed symmetrically on the left and right end surfaces in the axial direction of the outer ring 401 and the inner rings 402 and 402, respectively. Annular seal body 420 is accommodated in 421 and 422 symmetrically.

This annular seal body 420 is opposite to the ring portion 311 of the cage 410 via a ball 403. It is arrange | positioned at the inner- and outer-ring axial direction end surface part.

The annular seal body 420 is a non-contact type (non-contact with the inner rings 402A and 402B) that is inserted into the fitting groove 421a formed in the seal receiving groove 421 of the outer ring 401, and an inverted L-shaped metal core 42 Reinforced type rubber seal reinforced in 5 (for example -tolyl rubber, acrylic rubber or fluororubber) 426.

[0152] The rubber seal 426 includes a fitting portion 426a fitted into the fitting groove 421a and an annular plate portion 426b extending from the fitting portion 426a toward the inner rings 402A and 402B while being curved outward in the axial direction. Yes.

Here, in the fifth embodiment, a case where the double-row angular ball bearing 400 is replaced with a double-row combined angular ball bearing 7208A (contact angle 30 °) is taken as an example.

7208A has an inner ring inner diameter of 40 mm, an outer ring outer diameter of φ80 mm, and an axial sectional width (bearing unit width) B of 18 mm, so the sectional dimension ratio (B / H) is 0.9. Therefore, in the double-row anguillar ball bearing 400 of this embodiment, the cross-sectional dimension ratio (B2ZH2) is set to 0.90 (the inner ring axial cross-sectional width (bearing unit width) B2 is set to 18 mm).

As a result, the same effect as in the first embodiment in the fourth embodiment can be obtained, and it is needless to say that the radial load, the axial load in both directions, and the moment load can be received. It is possible to save 1Z2 in terms of dimensions, lower torque, and further increase rigidity.

Of course, if necessary, the cross-sectional dimension ratio (B2ZH2) may be set to be less than 0.90 or more than 0.90 (B2 / H2X 1.2).

Then, similarly to the first embodiment in the fourth embodiment described above, the pocket portion with respect to the axial distance L between the center of curvature of the pocket portion 313 and the tip of the ball engaging portion 314. 3 In the axial clearance between the ends of the ring 311 in the two opposing cages 410 with the center of curvature of 13 and the center of curvature of the ball 403 aligned, the pocket surface of the pocket 313 and the ball 403 Since the axial clearance is set to be small, the ball and cage can be reliably prevented from falling off due to the inner and outer ring tilts caused by the moment load.

[0155] In the fifth embodiment of the fourth embodiment, the moment rigidity is increased. For this reason, the ball pitch circle diameter may be shifted to the outer ring outer diameter side with a double row angular ball bearing, or the ball diameter or ball pitch circle diameter of each row may be changed with a double row angular ball bearing.

In any case, the application examples related to the structure of the annular seal body 420, whether or not it is mounted, the structure of the cage, and the like are based on the single row ball bearing described in the first embodiment. In addition, as in the first embodiment of the fourth embodiment, it should be used under either preload or clearance conditions.

Industrial applicability

In the case of a single row ball bearing, the sectional ratio (BZH) of the axial section width B to the radial section height H is (BZH) <0.63, and in the case of a double row ball bearing, the axial section width B2 And the radial cross-sectional height H2 (B2 / H2) is (B2ZH2) <1.2, it is possible to receive radial loads, axial loads in both directions, and moment loads. The spindle turning part used for the spindle turning part of machine tools that can achieve higher accuracy (higher rotation accuracy), higher rigidity, lower torque and lower heat generation, and further space saving. A ball bearing can be obtained.

Claims

The scope of the claims

[1] A single row ball bearing that is used for a main spindle turning portion of a machine tool, and in which a large number of balls are rotatably arranged between a raceway groove of an outer ring and a raceway groove of an inner ring,

A ball bearing for a turning part of a spindle of a machine tool, characterized in that a cross-sectional dimension ratio (BZH) between an axial sectional width B and a radial sectional height H is (BZH) <0.63.

[2] At least one side end surface between the outer ring and the inner ring is formed with a seal receiving groove portion, an annular seal body is disposed in the seal receiving groove portion, and the plurality of balls are positioned in the circumferential direction. An annular portion is formed on both sides in the axial direction of the pocket for holding the plurality of balls, and the annular portion has one of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. The concave groove portion that avoids contact with the intersection edge portion is formed in the circumferential direction at a position facing the intersection edge portion between the guide surface and the seal receiving groove portion as a guide surface. Ball bearings for spindle turning parts of machine tools as described in 1.

[3] A spindle turning device for a machine tool, comprising the spindle turning ball bearing according to claim 1 or 2 in a spindle turning portion for turning the spindle.

[4] A double row ball bearing that is used for a main spindle turning portion of a machine tool, and in which a large number of balls are rotatably arranged between a raceway groove of an outer ring and a raceway groove of an inner ring,

A ball bearing for a spindle turning part of a machine tool, characterized in that a cross-sectional dimension ratio (B2ZH2) between the axial sectional width B2 and the radial sectional height H2 is (B2ZH2) <1.2.

[5] A spindle turning device for a machine tool, characterized in that the spindle turning ball bearing according to claim 4 is provided in a spindle turning portion for turning the spindle.